1000 (number)

Template:Short description {{#invoke:Hatnote|hatnote}} Template:Use dmy dates Template:Infobox number Template:Sister project

1000 or one thousand is the natural number following 999 and preceding 1001. In most English-speaking countries, it can be written with or without a comma or sometimes a period separating the thousands digit: 1,000.

A group of one thousand units is sometimes known, from Ancient Greek, as a chiliad.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> A period of one thousand years may be known as a chiliad or, more often from Latin, as a millennium. The number 1000 is also sometimes described as a short thousand in medieval contexts where it is necessary to distinguish the Germanic concept of 1200 as a long thousand. It is the first 4-digit integer.

NotationEdit

The decimal representation for one thousand is
- 1000—a one followed by three zeros, in the general notation;
- 1 × 10³—in engineering notation, which for this number coincides with:
- 1 × 10³ exactly—in scientific normalized exponential notation;
- 1 E+3 exactly—in scientific E notation.
The SI prefix for a thousand units is "kilo-", abbreviated to "k"—for instance, a kilogram or "kg" is a thousand grams. This is sometimes extended to non-SI contexts, such as "ka" (kiloannum) being used as a shorthand for periods of 1000 years. In computer science, however, "kilo-" is used more loosely to mean 2 to the 10th power (1024).
In the SI writing style, a non-breaking space can be used as a thousands separator, i.e., to separate the digits of a number at every power of 1000.
Multiples of thousands are occasionally represented by replacing their last three zeros with the letter "K" or "k": for instance, writing "$30k" for $30 000 or using "Y2K" to denote the Year 2000 computer problem.
A thousand units of currency, especially dollars or pounds, are colloquially called a grand. In the United States, this is sometimes abbreviated with a "G" suffix.

In MathematicsEdit

A chiliagon is a 1000-sided polygon.<ref name="Chilia">Template:Cite OEIS</ref>

Numbers in the range 1001–1999Edit

1001 to 1099Edit

1001 = sphenic number (7 × 11 × 13), pentagonal number, pentatope number, palindromic number
1002 = sphenic number, Mertens function zero, abundant number, number of partitions of 22
1003 = the product of some prime p and the p^th prime, namely p = 17.
1004 = heptanacci number<ref name="Heptanacci numbers">Template:Cite OEIS</ref>
1005 = Mertens function zero, decagonal pyramidal number<ref name="auto62">Template:Cite OEIS</ref>
1006 = semiprime, product of two distinct isolated primes (2 and 503); unusual number; square-free number; number of compositions (ordered partitions) of 22 into squares; sum of two distinct pentatope numbers (5 and 1001); number of undirected Hamiltonian paths in 4 by 5 square grid graph;<ref>Template:Cite OEIS</ref> record gap between twin primes;<ref>Template:Cite OEIS</ref> number that is the sum of 7 positive 5th powers.<ref name="auto9">Template:Cite OEIS</ref> In decimal: equidigital number; when turned around, the number looks like a prime, 9001; its cube can be concatenated from other cubes, 1_0_1_8_1_0_8_216 ("_" indicates concatenation, 0 = 0³, 1 = 1³, 8 = 2³, 216 = 6³)<ref>Template:Cite OEIS</ref>
1007 = number that is the sum of 8 positive 5th powers<ref>Template:Cite OEIS</ref>
1008 = divisible by the number of primes below it
1009 = smallest four-digit prime, palindromic in bases 11, 15, 19, 24 and 28: (838₁₁, 474₁₅, 2F2₁₉, 1I1₂₄, 181₂₈). It is also a Lucky prime and Chen prime.
1010 = 10³ + 10,<ref>Template:Cite OEIS</ref> Mertens function zero
1011 = the largest n such that 2ⁿ contains 101 and does not contain 11011, Harshad number in bases 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75 (and 202 other bases), number of partitions of 1 into reciprocals of positive integers <= 16 Egyptian fraction<ref name=A020473>Template:Cite OEIS</ref>
1012 = ternary number, (32₁₀) quadruple triangular number (triangular number is 253),<ref>Template:Cite OEIS</ref> number of partitions of 1 into reciprocals of positive integers <= 17 Egyptian fraction<ref name=A020473/>
1013 = Sophie Germain prime,<ref name="Sophie Germain">Template:Cite OEIS</ref> centered square number,<ref name="Centered square numbers">Template:Cite OEIS</ref> Mertens function zero
1014 = 2¹⁰-10,<ref>Template:Cite OEIS</ref> Mertens function zero, sum of the nontriangular numbers between successive triangular numbers 78 and 91<ref>Template:Cite OEIS</ref>
1015 = square pyramidal number<ref name="Square pyramidal numbers">Template:Cite OEIS</ref>
1016 = member of the Mian–Chowla sequence,<ref name="Mian-Chowla">Template:Cite OEIS</ref> stella octangula number, number of surface points on a cube with edge-length 14<ref name="A005897" />
1017 = generalized triacontagonal number<ref>Template:Cite OEIS</ref>
1018 = Mertens function zero, 1018¹⁶ + 1 is prime<ref>Template:Cite OEIS</ref>
1019 = Sophie Germain prime,<ref name="Sophie Germain" /> safe prime,<ref name="Safe primes">Template:Cite OEIS</ref> Chen prime
1020 = polydivisible number
1021 = twin prime with 1019. It is also a Lucky prime.
1022 = Friedman number
1023 = sum of five consecutive primes (193 + 197 + 199 + 211 + 223);<ref>Template:Cite OEIS</ref> the number of three-dimensional polycubes with 7 cells;<ref>Template:Cite OEIS</ref> number of elements in a 9-simplex; highest number one can count to on one's fingers using binary; magic number used in Global Positioning System signals.
1024 = 32² = 4⁵ = 2¹⁰, the number of bytes in a kilobyte (in 1999, the IEC coined kibibyte to use for 1024 with kilobyte being 1000, but this convention has not been widely adopted). 1024 is the smallest 4-digit square and also a Friedman number.
1025 = Proth number 2¹⁰ + 1; member of Moser–de Bruijn sequence, because its base-4 representation (100001₄) contains only digits 0 and 1, or it's a sum of distinct powers of 4 (4⁵ + 4⁰); Jacobsthal-Lucas number; hypotenuse of primitive Pythagorean triangle
1026 = sum of two distinct powers of 2 (1024 + 2)
1027 = sum of the squares of the first eight primes; can be written from base 2 to base 18 using only the digits 0 to 9.
1028 = sum of totient function for first 58 integers; can be written from base 2 to base 18 using only the digits 0 to 9; number of primes <= 2¹³.<ref name="auto3">Template:Cite OEIS</ref>
1029 = can be written from base 2 to base 18 using only the digits 0 to 9.
1030 = generalized heptagonal number
1031 = exponent and number of ones for the fifth base-10 repunit prime,<ref>Template:Cite OEIS</ref> Sophie Germain prime,<ref name="Sophie Germain" /> super-prime, Chen prime
1032 = sum of two distinct powers of 2 (1024 + 8)
1033 = emirp, twin prime with 1031
1034 = sum of 12 positive 9th powers<ref>Template:Cite OEIS</ref>
1035 = 45th triangular number,<ref name="Triangular number">Template:Cite OEIS</ref> hexagonal number<ref name="Hexagonal number">Template:Cite OEIS</ref>
1036 = central polygonal number<ref name="auto11">Template:Cite OEIS</ref>
1037 = number in E-toothpick sequence<ref>Template:Cite OEIS</ref>
1038 = even integer that is an unordered sum of two primes in exactly n ways<ref>Template:Cite OEIS</ref>
1039 = prime of the form 8n+7,<ref>Template:Cite OEIS</ref> number of partitions of 30 that do not contain 1 as a part,<ref name="auto8">Template:Cite OEIS</ref> Chen prime, Lucky prime
1040 = 4⁵ + 4²: sum of distinct powers of 4.<ref name="auto6">Template:Cite OEIS</ref> The number of pieces that could be seen in a 6 × 6 × 6× 6 Rubik's Tesseract.
1041 = sum of 11 positive 5th powers<ref>Template:Cite OEIS</ref>
1042 = sum of 12 positive 5th powers<ref name="auto">Template:Cite OEIS</ref>
1043 = number whose sum of even digits and sum of odd digits are even<ref>Template:Cite OEIS</ref>
1044 = sum of distinct powers of 4<ref name="auto6"/>
1045 = octagonal number<ref>Template:Cite OEIS</ref>
1046 = coefficient of f(q) (3rd order mock theta function)<ref>Template:Cite OEIS</ref>
1047 = number of ways to split a strict composition of 18 into contiguous subsequences that have the same sum<ref>Template:Cite OEIS</ref>
1048 = number of partitions of 27 into squarefree parts<ref>Template:Cite OEIS</ref>
1049 = Sophie Germain prime,<ref name="Sophie Germain" /> highly cototient number,<ref name="highly cototient">Template:Cite OEIS</ref> Chen prime
1050 = 1050₈ to decimal becomes a pronic number (552₁₀),<ref>{{#invoke:citation/CS1|citation

|CitationClass=web }}</ref> number of parts in all partitions of 29 into distinct parts<ref name="auto46">Template:Cite OEIS</ref>

1051 = centered pentagonal number,<ref name="Centered pentagonal">Template:Cite OEIS</ref> centered decagonal number
1052 = sum of 9 positive 6th powers<ref>Template:Cite OEIS</ref>
1053 = triangular matchstick number<ref name="auto5" />
1054 = centered triangular number<ref>Template:Cite OEIS</ref>
1055 = sum of 12 positive 6th powers<ref>Template:Cite OEIS</ref>
1056 = pronic number<ref name="pronic number">Template:Cite OEIS</ref>
1057 = central polygonal number<ref>Template:Cite OEIS</ref>
1058 = sum of 4 positive 5th powers,<ref>Template:Cite OEIS</ref> area of a square with diagonal 46<ref name="area of a square with diagonal 2n">Template:Cite OEIS</ref>
1059 = number n such that n⁴ is written in the form of a sum of four positive 4th powers<ref>Template:Cite OEIS</ref>
1060 = sum of the first twenty-five primes from 2 through 97 (the number of primes less than 100),<ref>Template:Cite OEIS</ref> and sixth sum of 10 consecutive primes, starting with 23 through 131.<ref name="auto102">Template:Cite OEIS</ref>
1061 = emirp, twin prime with 1063, number of prime numbers between 1000 and 10000 (or, number of four-digit primes in decimal representation)<ref>Template:Cite OEIS</ref>
1062 = number that is not the sum of two palindromes<ref name="auto10">Template:Cite OEIS</ref>
1063 = super-prime, sum of seven consecutive primes (137 + 139 + 149 + 151 + 157 + 163 + 167); near-wall-sun-sun prime.<ref>Template:Cite OEIS</ref> It is also a twin prime with 1061.
1064 = sum of two positive cubes<ref>Template:Cite OEIS</ref>
1065 = generalized duodecagonal<ref>Template:Cite OEIS</ref>
1066 = number whose sum of their divisors is a square<ref>Template:Cite OEIS</ref>
1067 = number of strict integer partitions of 45 in which are empty or have smallest part not dividing the other ones<ref>Template:Cite OEIS</ref>
1068 = number that is the sum of 7 positive 5th powers,<ref name="auto9"/> total number of parts in all partitions of 15<ref name="auto16">Template:Cite OEIS</ref>
1069 = emirp<ref name="auto4">Template:Cite OEIS</ref>
1070 = number that is the sum of 9 positive 5th powers<ref name="auto2">Template:Cite OEIS</ref>
1071 = heptagonal number<ref name="heptagonal number">Template:Cite OEIS</ref>
1072 = centered heptagonal number<ref name="centered heptagonal number">Template:Cite OEIS</ref>
1073 = number that is the sum of 12 positive 5th powers<ref name="auto" />
1074 = number that is not the sum of two palindromes<ref name="auto10" />
1075 = number non-sum of two palindromes<ref name="auto10" />
1076 = number of strict trees weight 11<ref>Template:Cite OEIS</ref>
1077 = number where 7 outnumbers every other digit in the number<ref>Template:Cite OEIS</ref>
1078 = Euler transform of negative integers<ref>Template:Cite OEIS</ref>
1079 = every positive integer is the sum of at most 1079 tenth powers.
1080 = pentagonal number,<ref name="Pentagonal number">Template:Cite OEIS</ref> largely composite number<ref name="OEIS-A067128">Template:Cite OEIS</ref>
1081 = 46th triangular number,<ref name="Triangular number" /> member of Padovan sequence<ref name="Padovan sequence">Template:Cite OEIS</ref>
1082 = central polygonal number<ref name="auto11"/>
1083 = three-quarter square,<ref>Template:Cite OEIS</ref> number of partitions of 53 into prime parts<ref>Template:Cite OEIS</ref>
1084 = third spoke of a hexagonal spiral,<ref>Template:Cite OEIS</ref> 1084⁶⁴ + 1 is prime
1085 = number of partitions of n into distinct parts > or = 2<ref>Template:Cite OEIS</ref>
1086 = Smith number,<ref>Template:Cite OEIS</ref> sum of totient function for first 59 integers
1087 = super-prime, cousin prime, lucky prime<ref>Template:Cite OEIS</ref>
1088 = octo-triangular number, (triangular number result being 136)<ref>Template:Cite OEIS</ref> sum of two distinct powers of 2, (1024 + 64)<ref>Template:Cite OEIS</ref> number that is divisible by exactly seven primes with the inclusion of multiplicity<ref>Template:Cite OEIS</ref>
1089 = 33², nonagonal number, centered octagonal number, first natural number whose digits in its decimal representation get reversed when multiplied by 9.<ref>Template:Cite OEIS</ref>
1090 = sum of 5 positive 5th powers<ref>Template:Cite OEIS</ref>
1091 = cousin prime and twin prime with 1093
1092 = divisible by the number of primes below it
1093 = the smallest Wieferich prime (the only other known Wieferich prime is 3511<ref>Wells, D. The Penguin Dictionary of Curious and Interesting Numbers London: Penguin Group. (1987): 163</ref>), twin prime with 1091 and star number<ref name="Centered 12-gonal numbers">Template:Cite OEIS</ref>
1094 = sum of 9 positive 5th powers,<ref name="auto2" /> 1094⁶⁴ + 1 is prime
1095 = sum of 10 positive 5th powers,<ref>Template:Cite OEIS</ref> number that is not the sum of two palindromes
1096 = hendecagonal number,<ref>Template:Cite OEIS</ref> number of strict solid partitions of 18<ref name="auto43">Template:Cite OEIS</ref>
1097 = emirp,<ref name="auto4" /> Chen prime
1098 = multiple of 9 containing digit 9 in its base-10 representation<ref>Template:Cite OEIS</ref>
1099 = number where 9 outnumbers every other digit<ref>Template:Cite OEIS</ref>

1100 to 1199Edit

1100 = number of partitions of 61 into distinct squarefree parts<ref>Template:Cite OEIS</ref>
1101 = pinwheel number<ref name="Pinwheel">Template:Cite OEIS</ref>
1102 = sum of totient function for first 60 integers
1103 = Sophie Germain prime,<ref name="Sophie Germain" /> balanced prime<ref name="Balanced prime">Template:Cite OEIS</ref>
1104 = Keith number<ref name="Keith number">Template:Cite OEIS</ref>
1105 = 33² + 4² = 32² + 9² = 31² + 12² = 23² + 24², Carmichael number,<ref>{{#invoke:citation/CS1|citation

|CitationClass=web }}</ref> magic constant of n × n normal magic square and n-queens problem for n = 13, decagonal number,<ref name="Decagonal">{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> centered square number,<ref name="Centered square numbers" /> Fermat pseudoprime<ref name="auto93">Template:Cite OEIS</ref>

1106 = number of regions into which the plane is divided when drawing 24 ellipses<ref name="auto91">Template:Cite OEIS</ref>
1107 = number of non-isomorphic strict T₀ multiset partitions of weight 8<ref>Template:Cite OEIS</ref>
1108 = number k such that k⁶⁴ + 1 is prime
1109 = Friedlander-Iwaniec prime,<ref name="auto12">Template:Cite OEIS</ref> Chen prime
1110 = k such that 2^k + 3 is prime<ref>Template:Cite OEIS</ref>
1111 = 11 × 101, palindrome that is a product of two palindromic primes,<ref name="auto29">Template:Cite OEIS</ref> repunit<ref>{{#invoke:citation/CS1|citation

|CitationClass=web }}</ref>

1112 = k such that 9^k - 2 is a prime<ref>Template:Cite OEIS</ref>
1113 = number of strict partions of 40<ref name="auto20">Template:Cite OEIS</ref>
1114 = number of ways to write 22 as an orderless product of orderless sums<ref name="auto79">Template:Cite OEIS</ref>
1115 = number of partitions of 27 into a prime number of parts<ref name="auto70">Template:Cite OEIS</ref>
1116 = divisible by the number of primes below it
1117 = number of diagonally symmetric polyominoes with 16 cells,<ref name="auto23">Template:Cite OEIS</ref> Chen prime
1118 = number of unimodular 2 × 2 matrices having all terms in {0,1,...,21}<ref name="auto54">Template:Cite OEIS</ref>
1119 = number of bipartite graphs with 9 nodes<ref>Template:Cite OEIS</ref>
1120 = number k such that k⁶⁴ + 1 is prime
1121 = number of squares between 34² and 34⁴.<ref name="auto40">Template:Cite OEIS</ref>
1122 = pronic number,<ref name="pronic number" /> divisible by the number of primes below it
1123 = balanced prime<ref name="Balanced prime" />
1124 = Leyland number<ref name=A076980>Template:Cite OEIS</ref> using 2 & 10 (2¹⁰ + 10²), spy number
1125 = Achilles number
1126 = number of 2 × 2 non-singular integer matrices with entries from {0, 1, 2, 3, 4, 5}<ref>Template:Cite OEIS</ref>
1127 = maximal number of pieces that can be obtained by cutting an annulus with 46 cuts<ref name="auto73">Template:Cite OEIS</ref>
1128 = 47th triangular number,<ref name="Triangular number" /> 24th hexagonal number,<ref name="Hexagonal number" /> divisible by the number of primes below it (188 × 6).<ref>Template:Cite OEIS</ref> 1128 is the dimensional representation of the largest vertex operator algebra with central charge of 24, D₂₄.<ref>Template:Cite journal</ref>
1129 = number of lattice points inside a circle of radius 19<ref name="auto22">Template:Cite OEIS</ref>
1130 = skiponacci number<ref name="auto25">Template:Cite OEIS</ref>
1131 = number of edges in the hexagonal triangle T(26)<ref name="auto60">Template:Cite OEIS</ref>
1132 = number of simple unlabeled graphs with 9 nodes of 2 colors whose components are complete graphs<ref>Template:Cite OEIS</ref>
1133 = number of primitive subsequences of {1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15}<ref>Template:Cite OEIS</ref>
1134 = divisible by the number of primes below it, triangular matchstick number<ref name="auto5">Template:Cite OEIS</ref>
1135 = centered triangular number<ref name="auto52">Template:Cite OEIS</ref>
1136 = number of independent vertex sets and vertex covers in the 7-sunlet graph<ref>Template:Cite OEIS</ref>
1137 = sum of values of vertices at level 5 of the hyperbolic Pascal pyramid<ref>Template:Cite OEIS</ref>
1138 = recurring number in the works of George Lucas and his companies, beginning with his first feature film – THX 1138; particularly, a special code for Easter eggs on Star Wars DVDs.
1139 = wiener index of the windmill graph D(3,17)<ref name="auto90">Template:Cite OEIS</ref>
1140 = tetrahedral number<ref name="Tetrahedral nu">{{#invoke:citation/CS1|citation

|CitationClass=web }}</ref>

1141 = 7-Knödel number<ref name="auto21">Template:Cite OEIS</ref>
1142 = n such that n³² + 1 is prime,<ref name="auto51">Template:Cite OEIS</ref> spy number
1143 = number of set partitions of 8 elements with 2 connectors<ref>Template:Cite OEIS</ref>
1144 is not the sum of a pair of twin primes<ref name="auto99">Template:Cite OEIS</ref>
1145 = 5-Knödel number<ref name="auto14">Template:Cite OEIS</ref>
1146 is not the sum of a pair of twin primes<ref name="auto99"/>
1147 = 31 × 37 (a product of 2 successive primes)<ref>Template:Cite OEIS</ref>
1148 is not the sum of a pair of twin primes<ref name="auto99"/>
1149 = a product of two palindromic primes<ref>Template:Cite OEIS</ref>
1150 = number of 11-iamonds without bilateral symmetry.<ref>{{#invoke:citation/CS1|citation

|CitationClass=web }}</ref>

1151 = first prime following a prime gap of 22,<ref name="Prime gap">{{#invoke:citation/CS1|citation

|CitationClass=web }}</ref> Chen prime

1152 = highly totient number,<ref name="highly totient">{{#invoke:citation/CS1|citation

|CitationClass=web }}</ref> 3-smooth number (2⁷×3²), area of a square with diagonal 48,<ref name="area of a square with diagonal 2n"/> Achilles number

1153 = super-prime, Proth prime<ref name="Proth prime">{{#invoke:citation/CS1|citation

|CitationClass=web }}</ref>

1154 = 2 × 24² + 2 = number of points on surface of tetrahedron with edge length 24<ref name="auto59">Template:Cite OEIS</ref>
1155 = number of edges in the join of two cycle graphs, both of order 33,<ref name="auto89">Template:Cite OEIS</ref> product of first four odd primes (3*5*7*11)
1156 = 34², octahedral number,<ref name="Octahedral number">{{#invoke:citation/CS1|citation

|CitationClass=web }}</ref> centered pentagonal number,<ref name="Centered pentagonal" /> centered hendecagonal number.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>

1157 = smallest number that can be written as n^2+1 without any prime factors that can be written as a^2+1.<ref>{{#invoke:citation/CS1|citation

|CitationClass=web }}</ref>

1158 = number of points on surface of octahedron with edge length 17<ref name="auto61">Template:Cite OEIS</ref>
1159 = member of the Mian–Chowla sequence,<ref name=Mian-Chowla /> a centered octahedral number<ref name="auto7">Template:Cite OEIS</ref>
1160 = octagonal number<ref name="auto17">Template:Cite OEIS</ref>
1161 = sum of the first twenty-six primes
1162 = pentagonal number,<ref name="Pentagonal number" /> sum of totient function for first 61 integers
1163 = smallest prime > 34².<ref name="auto57">Template:Cite OEIS</ref> See Legendre's conjecture. Chen prime.
1164 = number of chains of multisets that partition a normal multiset of weight 8, where a multiset is normal if it spans an initial interval of positive integers<ref>Template:Cite OEIS</ref>
1165 = 5-Knödel number<ref name="auto14"/>
1166 = heptagonal pyramidal number<ref name="auto82">Template:Cite OEIS</ref>
1167 = number of rational numbers which can be constructed from the set of integers between 1 and 43<ref name="auto56">Template:Cite OEIS</ref>
1168 = antisigma(49)<ref>Template:Cite OEIS</ref>
1169 = highly cototient number<ref name="highly cototient" />
1170 = highest possible score in a National Academic Quiz Tournaments (NAQT) match
1171 = super-prime
1172 = number of subsets of first 14 integers that have a sum divisible by 14<ref>{{#invoke:citation/CS1|citation

|CitationClass=web }}</ref>

1173 = number of simple triangulation on a plane with 9 nodes<ref>{{#invoke:citation/CS1|citation

|CitationClass=web }}</ref>

1174 = number of widely totally strongly normal compositions of 16
1175 = maximal number of pieces that can be obtained by cutting an annulus with 47 cuts<ref name="auto73"/>
1176 = 48th triangular number<ref name="Triangular number" />
1177 = heptagonal number<ref name="heptagonal number" />
1178 = number of surface points on a cube with edge-length 15<ref name="A005897" />
1179 = number of different permanents of binary 7*7 matrices<ref>{{#invoke:citation/CS1|citation

|CitationClass=web }}</ref>

1180 = smallest number of non-integral partitions into non-integral power >1000.<ref>{{#invoke:citation/CS1|citation

|CitationClass=web }}</ref>

1181 = smallest k over 1000 such that 8*10^k-49 is prime.<ref>{{#invoke:citation/CS1|citation

|CitationClass=web }}</ref>

1182 = number of necklaces possible with 14 beads of 2 colors (that cannot be turned over)<ref>{{#invoke:citation/CS1|citation

|CitationClass=web }}</ref>

1183 = pentagonal pyramidal number
1184 = amicable number with 1210<ref>Template:Cite book</ref>
1185 = number of partitions of 45 into pairwise relatively prime parts<ref name="auto71">Template:Cite OEIS</ref>
1186 = number of diagonally symmetric polyominoes with 15 cells,<ref name="auto23"/> number of partitions of 54 into prime parts
1187 = safe prime,<ref name="Safe primes" /> Stern prime,<ref name="Stern prime">{{#invoke:citation/CS1|citation

|CitationClass=web }}</ref> balanced prime,<ref name="Balanced prime" /> Chen prime

1188 = first 4 digit multiple of 18 to contain 18<ref>{{#invoke:citation/CS1|citation

|CitationClass=web }}</ref>

1189 = number of squares between 35² and 35⁴.<ref name="auto40"/>
1190 = pronic number,<ref name="pronic number" /> number of cards to build a 28-tier house of cards<ref name="auto45">Template:Cite OEIS</ref>
1191 = 35² - 35 + 1 = H₃₅ (the 35th Hogben number)<ref name="auto77">Template:Cite OEIS</ref>
1192 = sum of totient function for first 62 integers
1193 = a number such that 4¹¹⁹³ - 3¹¹⁹³ is prime, Chen prime
1194 = number of permutations that can be reached with 8 moves of 2 bishops and 1 rook on a 3 × 3 chessboard<ref>{{#invoke:citation/CS1|citation

|CitationClass=web }}</ref>

1195 = smallest four-digit number for which a⁻¹(n) is an integer is a(n) is 2*a(n-1) - (-1)ⁿ<ref>oeis.org/A062092</ref>
1196 = <math>\sum_{k=1}^{38} \sigma(k)</math><ref name="auto38">Template:Cite OEIS</ref>
1197 = pinwheel number<ref name="Pinwheel" />
1198 = centered heptagonal number<ref name="centered heptagonal number" />
1199 = area of the 20th conjoined trapezoid<ref name="auto13">>Template:Cite OEIS</ref>

1200 to 1299Edit

1200 = the long thousand, ten "long hundreds" of 120 each, the traditional reckoning of large numbers in Germanic languages, the number of households the Nielsen ratings sample,<ref>Meehan, Eileen R., Why TV is not our fault: television programming, viewers, and who's really in control Lanham, MD: Rowman & Littlefield, 2005</ref> number k such that k⁶⁴ + 1 is prime
1201 = centered square number,<ref name="Centered square numbers" /> super-prime, centered decagonal number
1202 = number of regions the plane is divided into by 25 ellipses<ref name="auto91"/>
1203: first 4 digit number in the coordinating sequence for the (2,6,∞) tiling of the hyperbolic plane<ref>{{#invoke:citation/CS1|citation

|CitationClass=web }}</ref>

1204: magic constant of a 7 × 7 × 7 magic cube<ref>{{#invoke:citation/CS1|citation

|CitationClass=web }}</ref>

1205 = number of partitions of 28 such that the number of odd parts is a part<ref name="auto72">Template:Cite OEIS</ref>
1206 = 29-gonal number <ref>{{#invoke:citation/CS1|citation

|CitationClass=web }}</ref>

1207 = composite de Polignac number<ref name="auto53">Template:Cite OEIS</ref>
1208 = number of strict chains of divisors starting with the superprimorial A006939(3)<ref>Template:Cite OEIS</ref>
1209 = The product of all ordered non-empty subsets of {3,1} if {a,b} is a||b: 1209=1*3*13*31
1210 = amicable number with 1184<ref>Higgins, ibid.</ref>
1211 = composite de Polignac number<ref name="auto53"/>
1212 = <math>\sum_{k=0}^{17} p(k)</math>, where <math>p</math> is the number of partions of <math>k</math><ref>Template:Cite OEIS</ref>
1213 = emirp
1214 = sum of first 39 composite numbers,<ref name="auto94">Template:Cite OEIS</ref> spy number
1215 = number of edges in the hexagonal triangle T(27)<ref name="auto60"/>
1216 = nonagonal number<ref name="Nonagonal number">{{#invoke:citation/CS1|citation

|CitationClass=web }}</ref>

1217 = super-prime, Proth prime<ref name="Proth prime" />
1218 = triangular matchstick number<ref name="auto5"/>
1219 = Mertens function zero, centered triangular number<ref name="auto52"/>
1220 = Mertens function zero, number of binary vectors of length 16 containing no singletons<ref name="auto50">Template:Cite OEIS</ref>
1221 = product of the first two digit, and three digit repdigit
1222 = hexagonal pyramidal number
1223 = Sophie Germain prime,<ref name="Sophie Germain" /> balanced prime, 200th prime number<ref name="Balanced prime" />
1224 = number of edges in the join of two cycle graphs, both of order 34<ref name="auto89"/>
1225 = 35², 49th triangular number,<ref name="Triangular number" /> 2nd nontrivial square triangular number,<ref>{{#invoke:citation/CS1|citation

|CitationClass=web }}</ref> 25th hexagonal number,<ref name="Hexagonal number" /> and the smallest number >1 to be all three.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> Additionally a centered octagonal number,<ref name="Centered octagonal number">{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> icosienneagonal,<ref>Template:Cite OEIS</ref> hexacontagonal,<ref>Template:Cite OEIS</ref> and hecatonicositetragonal (124-gonal) number, and the sum of 5 consecutive odd cubes (1³ + 3³ + 5³ + 7³ + 9³)

1226 = number of rooted identity trees with 15 nodes <ref>{{#invoke:citation/CS1|citation

|CitationClass=web }}</ref>

1227 = smallest number representable as the sum of 3 triangular numbers in 27 ways<ref>{{#invoke:citation/CS1|citation

|CitationClass=web }}</ref>

1228 = sum of totient function for first 63 integers
1229 = Sophie Germain prime,<ref name="Sophie Germain" /> number of primes under 10,000, emirp
1230 = the Mahonian number: T(9, 6)<ref name="A008302">Template:Cite OEIS</ref>
1231 = smallest mountain emirp, as 121, smallest mountain number is 11 × 11
1232 = number of labeled ordered set of partitions of a 7-set into odd parts<ref>{{#invoke:citation/CS1|citation

|CitationClass=web }}</ref>

1233 = 12² + 33²
1234 = number of parts in all partitions of 30 into distinct parts,<ref name="auto46"/> smallest whole number containing all numbers from 1 to 4
1235 = excluding duplicates, contains the first four Fibonacci numbers <ref>{{#invoke:citation/CS1|citation

|CitationClass=web }}</ref>

1236 = 617 + 619: sum of twin prime pair<ref name="auto48">Template:Cite OEIS</ref>
1237 = prime of the form 2p-1
1238 = number of partitions of 31 that do not contain 1 as a part<ref name="auto8"/>
1239 = toothpick number in 3D<ref>{{#invoke:citation/CS1|citation

|CitationClass=web }}</ref>

1240 = square pyramidal number<ref name="Square pyramidal numbers" />
1241 = centered cube number,<ref>{{#invoke:citation/CS1|citation

|CitationClass=web }}</ref> spy number

1242 = decagonal number<ref name="Decagonal" />
1243 = composite de Polignac number<ref name="auto53"/>
1244 = number of complete partitions of 25<ref>Template:Cite OEIS</ref>
1245 = Number of labeled spanning intersecting set-systems on 5 vertices.<ref>oeis.org/A305843</ref>
1246 = number of partitions of 38 such that no part occurs more than once<ref>{{#invoke:citation/CS1|citation

|CitationClass=web }}</ref>

1247 = pentagonal number<ref name="Pentagonal number" />
1248 = the first four powers of 2 concatenated together
1249 = emirp, trimorphic number<ref>{{#invoke:citation/CS1|citation

|CitationClass=web }}</ref>

1250 = area of a square with diagonal 50<ref name="area of a square with diagonal 2n"/>
1251 = 2 × 25² + 1 = number of different 2 × 2 determinants with integer entries from 0 to 25<ref name="auto32">Template:Cite OEIS</ref>
1252 = 2 × 25² + 2 = number of points on surface of tetrahedron with edgelength 25<ref name="auto59"/>
1253 = number of partitions of 23 with at least one distinct part<ref name="auto66">Template:Cite OEIS</ref>
1254 = number of partitions of 23 into relatively prime parts<ref>Template:Cite OEIS</ref>
1255 = Mertens function zero, number of ways to write 23 as an orderless product of orderless sums,<ref name="auto79"/> number of partitions of 23<ref name="auto35">Template:Cite OEIS</ref>
1256 = 1 × 2 × (5²)² + 6,<ref name="ReferenceA">Template:Cite OEIS</ref> Mertens function zero
1257 = number of lattice points inside a circle of radius 20<ref name="auto22"/>
1258 = 1 × 2 × (5²)² + 8,<ref name="ReferenceA"/> Mertens function zero
1259 = highly cototient number<ref name="highly cototient" />
1260 = the 16th highly composite number,<ref name="Highly composite">{{#invoke:citation/CS1|citation

|CitationClass=web }}</ref> pronic number,<ref name="pronic number" /> the smallest vampire number,<ref name="Vampire number">{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> sum of totient function for first 64 integers, number of strict partions of 41<ref name="auto20"/> and appears twice in the Book of Revelation

1261 = star number,<ref name="Centered 12-gonal numbers" /> Mertens function zero
1262 = maximal number of regions the plane is divided into by drawing 36 circles<ref name="auto27">Template:Cite OEIS</ref>
1263 = rounded total surface area of a regular tetrahedron with edge length 27<ref name="auto74">Template:Cite OEIS</ref>
1264 = sum of the first 27 primes
1265 = number of rooted trees with 43 vertices in which vertices at the same level have the same degree<ref name="auto28">Template:Cite OEIS</ref>
1266 = centered pentagonal number,<ref name="Centered pentagonal" /> Mertens function zero
1267 = 7-Knödel number<ref name="auto21"/>
1268 = number of partitions of 37 into prime power parts<ref name="auto87">Template:Cite OEIS</ref>
1269 = least number of triangles of the Spiral of Theodorus to complete 11 revolutions<ref name="auto85">Template:Cite OEIS</ref>
1270 = 25 + 24×26 + 23×27,<ref>Template:Cite OEIS</ref> Mertens function zero
1271 = sum of first 40 composite numbers<ref name="auto94"/>
1272 = sum of first 41 nonprimes<ref name="ReferenceB">Template:Cite OEIS</ref>
1273 = 19 × 67 = 19 × prime(19)<ref name="cite OEIS|A033286|n * primen">Template:Cite OEIS</ref>
1274 = sum of the nontriangular numbers between successive triangular numbers
1275 = 50th triangular number,<ref name="Triangular number" /> equivalently the sum of the first 50 natural numbers
1276 = number of irredundant sets in the 25-cocktail party graph<ref name="auto34">Template:Cite OEIS</ref>
1277 = the start of a prime constellation of length 9 (a "prime nonuple")
1278 = number of Narayana's cows and calves after 20 years<ref name="auto98">Template:Cite OEIS</ref>
1279 = Mertens function zero, Mersenne prime exponent
1280 = Mertens function zero, number of parts in all compositions of 9<ref>Template:Cite OEIS</ref>
1281 = octagonal number<ref name="auto17"/>
1282 = Mertens function zero, number of partitions of 46 into pairwise relatively prime parts<ref name="auto71"/>
1283 = safe prime<ref name="Safe primes" />
1284 = 641 + 643: sum of twin prime pair<ref name="auto48"/>
1285 = Mertens function zero, number of free nonominoes, number of parallelogram polyominoes with 10 cells.<ref>Template:Cite OEIS</ref>
1286 = number of inequivalent connected planar figures that can be formed from five 1 X 2 rectangles (or dominoes) such that each pair of touching rectangles shares exactly one edge, of length 1, and the adjacency graph of the rectangles is a tree<ref>Template:Cite OEIS</ref>
1287 = <math>{13 \choose 5}</math><ref>Template:Cite OEIS</ref>
1288 = heptagonal number<ref name="heptagonal number" />
1289 = Sophie Germain prime,<ref name="Sophie Germain" /> Mertens function zero
1290 = <math>\frac{1289 + 1291}{2}</math>, average of a twin prime pair<ref>Template:Cite OEIS</ref>
1291 = largest prime < 6⁴,<ref>Template:Cite OEIS</ref> Mertens function zero
1292 = number such that phi(1292) = phi(sigma(1292)),<ref>Template:Cite OEIS</ref> Mertens function zero
1293 = <math>\sum_{j=1}^n j \times prime(j)</math><ref>Template:Cite OEIS</ref>
1294 = rounded volume of a regular octahedron with edge length 14<ref name="auto84">Template:Cite OEIS</ref>
1295 = number of edges in the join of two cycle graphs, both of order 35<ref name="auto89"/>
1296 = 36² = 6⁴, sum of the cubes of the first eight positive integers, the number of rectangles on a normal 8 × 8 chessboard, also the maximum font size allowed in Adobe InDesign, number of combinations of 2 characters(00-ZZ)
1297 = super-prime, Mertens function zero, pinwheel number<ref name="Pinwheel" />
1298 = number of partitions of 55 into prime parts
1299 = Mertens function zero, number of partitions of 52 such that the smallest part is greater than or equal to number of parts<ref name="auto75">Template:Cite OEIS</ref>

1300 to 1399Edit

1300 = Sum of the first 4 fifth powers, Mertens function zero, largest possible win margin in an NAQT match; smallest even odd-factor hyperperfect number
1301 = centered square number,<ref name="Centered square numbers" /> Honaker prime,<ref name="auto39">Template:Cite OEIS</ref> number of trees with 13 unlabeled nodes<ref>Template:Cite OEIS</ref>
1302 = Mertens function zero, number of edges in the hexagonal triangle T(28)<ref name="auto60"/>
1303 = prime of form 21n+1 and 31n+1<ref>{{#invoke:citation/CS1|citation

|CitationClass=web }}</ref><ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>

1304 = sum of 1304₆ and 1304 ₉ which is 328+976
1305 = triangular matchstick number<ref name="auto5"/>
1306 = Mertens function zero. In base 10, raising the digits of 1306 to powers of successive integers equals itself: Template:Nowrap 135, 175, 518, and 598 also have this property. Centered triangular number.<ref name="auto52"/>
1307 = safe prime<ref name="Safe primes" />
1308 = sum of totient function for first 65 integers
1309 = the first sphenic number followed by two consecutive such number
1310 = smallest number in the middle of a set of three sphenic numbers
1311 = number of integer partitions of 32 with no part dividing all the others<ref name="auto30">Template:Cite OEIS</ref>
1312 = member of the Mian-Chowla sequence;<ref name=Mian-Chowla />
1313 = sum of all parts of all partitions of 14 <ref>{{#invoke:citation/CS1|citation

|CitationClass=web }}</ref>

1314 = number of integer partitions of 41 whose distinct parts are connected<ref name="auto86">Template:Cite OEIS</ref>
1315 = 10^(2n+1)-7*10^n-1 is prime.<ref>{{#invoke:citation/CS1|citation

|CitationClass=web }}</ref>

1316 = Euler transformation of sigma(11)<ref>{{#invoke:citation/CS1|citation

|CitationClass=web }}</ref>

1317 = 1317 Only odd four digit number to divide the concatenation of all number up to itself in base 25<ref>{{#invoke:citation/CS1|citation

|CitationClass=web }}</ref>

1318⁵¹² + 1 is prime,<ref>Template:Cite OEIS</ref> Mertens function zero
1319 = safe prime<ref name="Safe primes" />
1320 = 659 + 661: sum of twin prime pair<ref name="auto48"/>
1321 = Friedlander-Iwaniec prime<ref name="auto12"/>
1322 = area of the 21st conjoined trapezoid<ref name="auto13"/>
1323 = Achilles number
1324 = if D(n) is the nth representation of 1, 2 arranged lexicographically. 1324 is the first non-1 number which is D(D(x))<ref>{{#invoke:citation/CS1|citation

|CitationClass=web }}</ref>

1325 = Markov number,<ref name="Markov number">{{#invoke:citation/CS1|citation

|CitationClass=web }}</ref> centered tetrahedral number<ref name="auto42">Template:Cite OEIS</ref>

1326 = 51st triangular number,<ref name="Triangular number" /> hexagonal number,<ref name="Hexagonal number" /> Mertens function zero
1327 = first prime followed by 33 consecutive composite numbers
1328 = sum of totient function for first 66 integers
1329 = Mertens function zero, sum of first 41 composite numbers<ref name="auto94"/>
1330 = tetrahedral number,<ref name="Tetrahedral nu"/> forms a Ruth–Aaron pair with 1331 under second definition
1331 = 11³, centered heptagonal number,<ref name="centered heptagonal number" /> forms a Ruth–Aaron pair with 1330 under second definition. This is the only non-trivial cube of the form x² + x − 1, for x = 36.
1332 = pronic number<ref name="pronic number" />
1333 = 37² - 37 + 1 = H₃₇ (the 37th Hogben number)<ref name="auto77"/>
1334 = maximal number of regions the plane is divided into by drawing 37 circles<ref name="auto27"/>
1335 = pentagonal number,<ref name="Pentagonal number" /> Mertens function zero
1336 = sum of gcd(x, y) for 1 <= x, y <= 24,<ref>Template:Cite OEIS</ref> Mertens function zero
1337 = Used in the novel form of spelling called leet. Approximate melting point of gold in kelvins.
1338 = atomic number of the noble element of period 18,<ref>Template:Cite OEIS</ref> Mertens function zero
1339 = First 4 digit number to appear twice in the sequence of sum of cubes of primes dividing n<ref>{{#invoke:citation/CS1|citation

|CitationClass=web }}</ref>

1340 = k such that 5 × 2^k - 1 is prime<ref name="auto69">Template:Cite OEIS</ref>
1341 = First mountain number with 2 jumps of more than one.
1342 = <math>\sum_{k=1}^{40} \sigma(k)</math>,<ref name="auto38"/> Mertens function zero
1343 = cropped hexagone<ref name="auto44">Template:Cite OEIS</ref>
1344 = 37² - 5², the only way to express 1344 as a difference of prime squares<ref name="auto96">Template:Cite OEIS</ref>
1345 = k such that k, k+1 and k+2 are products of two primes<ref name="auto81">Template:Cite OEIS</ref>
1346 = number of locally disjointed rooted trees with 10 nodes<ref>{{#invoke:citation/CS1|citation

|CitationClass=web }}</ref>

1347 = concatenation of first 4 Lucas numbers <ref>{{#invoke:citation/CS1|citation

|CitationClass=web }}</ref>

1348 = number of ways to stack 22 pennies such that every penny is in a stack of one or two<ref>{{#invoke:citation/CS1|citation

|CitationClass=web }}</ref>

1349 = Stern-Jacobsthal number<ref name="auto15">Template:Cite OEIS</ref>
1350 = nonagonal number<ref name="Nonagonal number" />
1351 = number of partitions of 28 into a prime number of parts<ref name="auto70"/>
1352 = number of surface points on a cube with edge-length 16,<ref name="A005897" /> Achilles number
1353 = 2 × 26² + 1 = number of different 2 × 2 determinants with integer entries from 0 to 26<ref name="auto32"/>
1354 = 2 × 26² + 2 = number of points on surface of tetrahedron with edgelength 26<ref name="auto59"/>
1355 appears for the first time in the Recamán's sequence at n = 325,374,625,245.<ref>Template:Cite OEIS</ref> Or in other words A057167(1355) = 325,374,625,245<ref>Template:Cite OEIS</ref><ref>Template:Cite OEIS</ref>
1356 is not the sum of a pair of twin primes<ref name="auto99"/>
1357 = number of nonnegative solutions to x² + y² ≤ 41²<ref name="auto65">Template:Cite OEIS</ref>
1358 = rounded total surface area of a regular tetrahedron with edge length 28<ref name="auto74"/>
1359 is the 42d term of Flavius Josephus's sieve<ref>Template:Cite OEIS</ref>
1360 = 37² - 3², the only way to express 1360 as a difference of prime squares<ref name="auto96"/>
1361 = first prime following a prime gap of 34,<ref name="Prime gap" /> centered decagonal number, 3rd Mills' prime, Honaker prime<ref name="auto39"/>
1362 = number of achiral integer partitions of 48<ref name="auto64">Template:Cite OEIS</ref>
1363 = the number of ways to modify a circular arrangement of 14 objects by swapping one or more adjacent pairs<ref>Template:Cite OEIS</ref>
1364 = Lucas number<ref>Template:Cite OEIS</ref>
1365 = pentatope number<ref name="Pentatope number">{{#invoke:citation/CS1|citation

|CitationClass=web }}</ref>

1366 = Arima number, after Yoriyuki Arima who in 1769 constructed this sequence as the number of moves of the outer ring in the optimal solution for the Chinese Rings puzzle<ref>Template:Cite OEIS</ref>
1367 = safe prime,<ref name="Safe primes" /> balanced prime, sum of three, nine, and eleven consecutive primes (449 + 457 + 461, 131 + 137 + 139 + 149 + 151 + 157 + 163 + 167 + 173, and 101 + 103 + 107 + 109 + 113 + 127 + 131 + 137 + 139 + 149 + 151),<ref name="Balanced prime" />
1368 = number of edges in the join of two cycle graphs, both of order 36<ref name="auto89"/>
1369 = 37², centered octagonal number<ref name="Centered octagonal number" />
1370 = σ₂(37): sum of squares of divisors of 37<ref name="auto76">Template:Cite OEIS</ref>
1371 = sum of the first 28 primes
1372 = Achilles number
1373 = number of lattice points inside a circle of radius 21<ref name="auto22"/>
1374 = number of unimodular 2 × 2 matrices having all terms in {0,1,...,23}<ref name="auto54"/>
1375 = decagonal pyramidal number<ref name="auto62"/>
1376 = primitive abundant number (abundant number all of whose proper divisors are deficient numbers)<ref name="auto92">Template:Cite OEIS</ref>
1377 = maximal number of pieces that can be obtained by cutting an annulus with 51 cuts<ref name="auto73"/>
1378 = 52nd triangular number<ref name="Triangular number" />
1379 = magic constant of n × n normal magic square and n-queens problem for n = 14.
1380 = number of 8-step mappings with 4 inputs<ref name="auto95">Template:Cite OEIS</ref>
1381 = centered pentagonal number<ref name="Centered pentagonal" /> Mertens function zero
1382 = first 4 digit tetrachi number <ref>{{#invoke:citation/CS1|citation

|CitationClass=web }}</ref>

1383 = 3 × 461. 10¹³⁸³ + 7 is prime<ref>Template:Cite OEIS</ref>
1384 = <math>\sum_{k=1}^{41} \sigma(k)</math><ref name="auto38"/>
1385 = up/down number<ref>Template:Cite OEIS</ref>
1386 = octagonal pyramidal number<ref>Template:Cite OEIS</ref>
1387 = 5th Fermat pseudoprime of base 2,<ref>{{#invoke:citation/CS1|citation

|CitationClass=web }}</ref> 22nd centered hexagonal number and the 19th decagonal number,<ref name="Decagonal" /> second Super-Poulet number.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>

1388 = 4 × 19² - 3 × 19 + 1 and is therefore on the x-axis of Ulams spiral<ref>Template:Cite OEIS</ref>
1389 = sum of first 42 composite numbers<ref name="auto94"/>
1390 = sum of first 43 nonprimes<ref name="ReferenceB"/>
1391 = number of rational numbers which can be constructed from the set of integers between 1 and 47<ref name="auto56"/>
1392 = number of edges in the hexagonal triangle T(29)<ref name="auto60"/>
1393 = 7-Knödel number<ref name="auto21"/>
1394 = sum of totient function for first 67 integers
1395 = vampire number,<ref name="Vampire number" /> member of the Mian–Chowla sequence<ref name=Mian-Chowla /> triangular matchstick number<ref name="auto5"/>
1396 = centered triangular number<ref name="auto52"/>
1397 = <math>\left \lfloor 5^{\frac{9}{2}} \right \rfloor</math><ref>Template:Cite OEIS</ref>
1398 = number of integer partitions of 40 whose distinct parts are connected<ref name="auto86"/>
1399 = emirp<ref>Template:Cite OEIS</ref>

1400 to 1499Edit

1400 = number of sum-free subsets of {1, ..., 15}<ref name="auto41">Template:Cite OEIS</ref>
1401 = pinwheel number<ref name="Pinwheel" />
1402 = number of integer partitions of 48 whose augmented differences are distinct,<ref name="auto19">Template:Cite OEIS</ref> number of signed trees with 8 nodes<ref>Template:Cite OEIS</ref>
1403 = smallest x such that M(x) = 11, where M() is Mertens function<ref name="ReferenceC">Template:Cite OEIS</ref>
1404 = heptagonal number<ref name="heptagonal number" />
1405 = 26² + 27², 7² + 8² + ... + 16², centered square number<ref name="Centered square numbers" />
1406 = pronic number,<ref name="pronic number" /> semi-meandric number<ref>{{#invoke:citation/CS1|citation

|CitationClass=web }}</ref>

1407 = 38² - 38 + 1 = H₃₈ (the 38th Hogben number)<ref name="auto77"/>
1408 = maximal number of regions the plane is divided into by drawing 38 circles<ref name="auto27"/>
1409 = super-prime, Sophie Germain prime,<ref name="Sophie Germain" /> smallest number whose eighth power is the sum of 8 eighth powers, Proth prime<ref name="Proth prime" />
1410 = denominator of the 46th Bernoulli number<ref>Template:Cite OEIS</ref>
1411 = LS(41)<ref name="ReferenceD">Template:Cite OEIS</ref>
1412 = LS(42),<ref name="ReferenceD"/> spy number
1413 = LS(43)<ref name="ReferenceD"/>
1414 = smallest composite that when added to sum of prime factors reaches a prime after 27 iterations<ref name="auto37">Template:Cite OEIS</ref>
1415 = the Mahonian number: T(8, 8)<ref name="A008302" />
1416 = LS(46)<ref name="ReferenceD"/>
1417 = number of partitions of 32 in which the number of parts divides 32<ref name="auto63">Template:Cite OEIS</ref>
1418 = smallest x such that M(x) = 13, where M() is Mertens function<ref name="ReferenceC"/>
1419 = Zeisel number<ref name="Zeisel number">{{#invoke:citation/CS1|citation

|CitationClass=web }}</ref>

1420 = Number of partitions of 56 into prime parts
1421 = maximum dimension of Euclidean spaces which suffice for every smooth compact Riemannian 29-manifold to be realizable as a sub-manifold,<ref name="ReferenceE">Template:Cite OEIS</ref> spy number
1422 = number of partitions of 15 with two parts marked<ref>Template:Cite OEIS</ref>
1423 = 200 + 1223 and the 200th prime is 1223<ref name="auto47">Template:Cite OEIS</ref>
1424 = number of nonnegative solutions to x² + y² ≤ 42²<ref name="auto65"/>
1425 = self-descriptive number in base 5
1426 = sum of totient function for first 68 integers, pentagonal number,<ref name="Pentagonal number" /> number of strict partions of 42<ref name="auto20"/>
1427 = twin prime together with 1429<ref>Template:Cite OEIS</ref>
1428 = number of complete ternary trees with 6 internal nodes, or 18 edges<ref>Template:Cite OEIS</ref>
1429 = number of partitions of 53 such that the smallest part is greater than or equal to number of parts<ref name="auto75"/>
1430 = Catalan number<ref>{{#invoke:citation/CS1|citation

|CitationClass=web }}</ref>

1431 = 53rd triangular number,<ref name="Triangular number" /> hexagonal number<ref name="Hexagonal number" />
1432 = member of Padovan sequence<ref name="Padovan sequence" />
1433 = super-prime, Honaker prime,<ref name="auto39"/> typical port used for remote connections to Microsoft SQL Server databases
1434 = rounded volume of a regular tetrahedron with edge length 23<ref name="auto88">Template:Cite OEIS</ref>
1435 = vampire number;<ref name="Vampire number" /> the standard railway gauge in millimetres, equivalent to Template:Convert
1436 = discriminant of a totally real cubic field<ref name="ReferenceF">Template:Cite OEIS</ref>
1437 = smallest number of complexity 20: smallest number requiring 20 1's to build using +, * and ^<ref name="auto49">Template:Cite OEIS</ref>
1438 = k such that 5 × 2^k - 1 is prime<ref name="auto69"/>
1439 = Sophie Germain prime,<ref name="Sophie Germain" /> safe prime<ref name="Safe primes" />
1440 = a highly totient number,<ref name="highly totient" /> a largely composite number<ref name="OEIS-A067128"/> and a 481-gonal number. Also, the number of minutes in one day, the size in kibibytes (units of 1,024 bytes) of a standard Template:Sfrac floppy disk, and the horizontal resolution of WXGA(II) computer displays
1441 = star number<ref name="Centered 12-gonal numbers" />
1442 = number of parts in all partitions of 31 into distinct parts<ref name="auto46"/>
1443 = the sum of the second trio of three-digit permutable primes in decimal: 337, 373, and 733. Also the number of edges in the join of two cycle graphs, both of order 37<ref name="auto89"/>
1444 = 38², smallest pandigital number in Roman numerals
1445 = <math>\sum_{k=0}^3 \left( \binom{3}{k} \times \binom{3+k}{k} \right) ^2</math><ref>Template:Cite OEIS</ref>
1446 = number of points on surface of octahedron with edge length 19<ref name="auto61"/>
1447 = super-prime, happy number
1448 = number k such that phi(prime(k)) is a square<ref name="auto55">Template:Cite OEIS</ref>
1449 = Stella octangula number
1450 = σ₂(34): sum of squares of divisors of 34<ref name="auto76"/>
1451 = Sophie Germain prime<ref name="Sophie Germain" />
1452 = first Zagreb index of the complete graph K₁₂<ref name="auto100">Template:Cite OEIS</ref>
1453 = Sexy prime with 1459
1454 = 3 × 22² + 2 = number of points on surface of square pyramid of side-length 22<ref name="auto58">Template:Cite OEIS</ref>
1455 = k such that geometric mean of phi(k) and sigma(k) is an integer<ref name="auto68">Template:Cite OEIS</ref>
1456 = number of regions in regular 15-gon with all diagonals drawn<ref>Template:Cite OEIS</ref>
1457 = 2 × 27² − 1 = a twin square<ref name="auto83">Template:Cite OEIS</ref>
1458 = maximum determinant of an 11 by 11 matrix of zeroes and ones, 3-smooth number (2×3⁶)
1459 = Sexy prime with 1453, sum of nine consecutive primes (139 + 149 + 151 + 157 + 163 + 167 + 173 + 179 + 181), Pierpont prime
1460 = The number of years that would have to pass in the Julian calendar in order to accrue a full year's worth of leap days.
1461 = number of partitions of 38 into prime power parts<ref name="auto87"/>
1462 = (35 - 1) × (35 + 8) = the first Zagreb index of the wheel graph with 35 vertices<ref>Template:Cite OEIS</ref>
1463 = total number of parts in all partitions of 16<ref name="auto16"/>
1464 = rounded total surface area of a regular icosahedron with edge length 13<ref>Template:Cite OEIS</ref>
1465 = 5-Knödel number<ref name="auto14"/>
1466 = <math>\sum_{k=1}^{256} d(k)</math>, where <math>d(k)</math> = number of divisors of <math>k</math><ref>Template:Cite OEIS</ref>
1467 = number of partitions of 39 with zero crank<ref>Template:Cite OEIS</ref>
1468 = number of polyhexes with 11 cells that tile the plane by translation<ref>Template:Cite OEIS</ref>
1469 = octahedral number,<ref name="Octahedral number" /> highly cototient number<ref name="highly cototient" />
1470 = pentagonal pyramidal number,<ref name="Pentagonal pyramidal number">{{#invoke:citation/CS1|citation

|CitationClass=web }}</ref> sum of totient function for first 69 integers

1471 = super-prime, centered heptagonal number<ref name="centered heptagonal number" />
1472 = number of overpartitions of 15<ref>Template:Cite OEIS</ref>
1473 = cropped hexagone<ref name="auto44"/>
1474 = <math>\frac{44(44 + 1)}{2} + \frac{44^2}{4}</math>: triangular number plus quarter square (i.e., A000217(44) + A002620(44))<ref>Template:Cite OEIS</ref>
1475 = number of partitions of 33 into parts each of which is used a different number of times<ref name="ReferenceG">Template:Cite OEIS</ref>
1476 = coreful perfect number<ref name="auto31">Template:Cite OEIS</ref>
1477 = 7-Knödel number<ref name="auto21"/>
1478 = total number of largest parts in all compositions of 11<ref>Template:Cite OEIS</ref>
1479 = number of planar partitions of 12<ref>Template:Cite OEIS</ref>
1480 = sum of the first 29 primes
1481 = Sophie Germain prime<ref name="Sophie Germain" />
1482 = pronic number,<ref name="pronic number" /> number of unimodal compositions of 15 where the maximal part appears once<ref>Template:Cite OEIS</ref>
1483 = 39² - 39 + 1 = H₃₉ (the 39th Hogben number)<ref name="auto77"/>
1484 = maximal number of regions the plane is divided into by drawing 39 circles<ref name="auto27"/>
1485 = 54th triangular number<ref name="Triangular number" />
1486 = number of strict solid partitions of 19<ref name="auto43"/>
1487 = safe prime<ref name="Safe primes" />
1488 = triangular matchstick number,<ref name="auto5"/> commonly used as a hate symbol
1489 = centered triangular number<ref name="auto52"/>
1490 = tetranacci number<ref>{{#invoke:citation/CS1|citation

|CitationClass=web }}</ref>

1491 = nonagonal number,<ref name="Nonagonal number" /> Mertens function zero
1492 = discriminant of a totally real cubic field,<ref name="ReferenceF"/> Mertens function zero
1493 = Stern prime<ref name="Stern prime" />
1494 = sum of totient function for first 70 integers
1495 = 9###<ref>Template:Cite OEIS</ref>
1496 = square pyramidal number<ref name="Square pyramidal numbers" />
1497 = skiponacci number<ref name="auto25"/>
1498 = number of flat partitions of 41<ref name="auto26">Template:Cite OEIS</ref>
1499 = Sophie Germain prime,<ref name="Sophie Germain" /> super-prime

1500 to 1599Edit

1500 = hypotenuse in three different Pythagorean triangles<ref name="auto101">Template:Cite OEIS</ref>
1501 = centered pentagonal number<ref name="Centered pentagonal" />
1502 = number of pairs of consecutive integers x, x+1 such that all prime factors of both x and x+1 are at most 47<ref name="auto80">Template:Cite OEIS</ref>
1503 = least number of triangles of the Spiral of Theodorus to complete 12 revolutions<ref name="auto85"/>
1504 = primitive abundant number (abundant number all of whose proper divisors are deficient numbers)<ref name="auto92"/>
1505 = number of integer partitions of 41 with distinct differences between successive parts<ref>Template:Cite OEIS</ref>
1506 = number of Golomb partitions of 28<ref>Template:Cite OEIS</ref>
1507 = number of partitions of 32 that do not contain 1 as a part<ref name="auto8"/>
1508 = heptagonal pyramidal number<ref name="auto82"/>
1509 = pinwheel number<ref name="Pinwheel" />
1510 = deficient number, odious number
1511 = Sophie Germain prime,<ref name="Sophie Germain" /> balanced prime<ref name="Balanced prime" />
1512 = k such that geometric mean of phi(k) and sigma(k) is an integer<ref name="auto68"/>
1513 = centered square number<ref name="Centered square numbers" />
1514 = sum of first 44 composite numbers<ref name="auto94"/>
1515 = maximum dimension of Euclidean spaces which suffice for every smooth compact Riemannian 30-manifold to be realizable as a sub-manifold<ref name="ReferenceE"/>
1516 = <math>\left \lfloor 9^\frac{10}{3} \right \rfloor </math><ref>Template:Cite OEIS</ref>
1517 = number of lattice points inside a circle of radius 22<ref name="auto22"/>
1518 = sum of first 32 semiprimes,<ref>Template:Cite OEIS</ref> Mertens function zero
1519 = number of polyhexes with 8 cells,<ref>Template:Cite OEIS</ref> Mertens function zero
1520 = pentagonal number,<ref name="Pentagonal number" /> Mertens function zero, forms a Ruth–Aaron pair with 1521 under second definition
1521 = 39², Mertens function zero, centered octagonal number,<ref name="Centered octagonal number" /> forms a Ruth–Aaron pair with 1520 under second definition
1522 = k such that 5 × 2^k - 1 is prime<ref name="auto69"/>
1523 = super-prime, Mertens function zero, safe prime,<ref name="Safe primes" /> member of the Mian–Chowla sequence<ref name=Mian-Chowla />
1524 = Mertens function zero, k such that geometric mean of phi(k) and sigma(k) is an integer<ref name="auto68"/>
1525 = heptagonal number,<ref name="heptagonal number" /> Mertens function zero
1526 = number of conjugacy classes in the alternating group A₂₇<ref name="auto33">Template:Cite OEIS</ref>
1527 = number of 2-dimensional partitions of 11,<ref>Template:Cite OEIS</ref> Mertens function zero
1528 = Mertens function zero, rounded total surface area of a regular octahedron with edge length 21<ref>Template:Cite OEIS</ref>
1529 = composite de Polignac number<ref name="auto53"/>
1530 = vampire number<ref name="Vampire number" />
1531 = prime number, centered decagonal number, Mertens function zero
1532 = number of series-parallel networks with 9 unlabeled edges,<ref>Template:Cite OEIS</ref> Mertens function zero
1533 = 21 × 73 = 21 × 21st prime<ref name="cite OEIS|A033286|n * primen"/>
1534 = number of achiral integer partitions of 50<ref name="auto64"/>
1535 = Thabit number
1536 = a common size of microplate, 3-smooth number (2⁹×3), number of threshold functions of exactly 4 variables<ref>Template:Cite OEIS</ref>
1537 = Keith number,<ref name="Keith number" /> Mertens function zero
1538 = number of surface points on a cube with edge-length 17<ref name="A005897">Template:Cite OEIS</ref>
1539 = maximal number of pieces that can be obtained by cutting an annulus with 54 cuts<ref name="auto73"/>
1540 = 55th triangular number,<ref name="Triangular number" /> hexagonal number,<ref name="Hexagonal number" /> decagonal number,<ref name="Decagonal" /> tetrahedral number<ref name="Tetrahedral nu"/>
1541 = octagonal number<ref name="auto17"/>
1542 = k such that 2^k starts with k<ref>Template:Cite OEIS</ref>
1543 = prime dividing all Fibonacci sequences,<ref>Template:Cite OEIS</ref> Mertens function zero
1544 = Mertens function zero, number of partitions of integer partitions of 17 where all parts have the same length<ref>Template:Cite OEIS</ref>
1545 = number of reversible string structures with 9 beads using exactly three different colors<ref>Template:Cite OEIS</ref>
1546 = number of 5 X 5 binary matrices with at most one 1 in each row and column,<ref>Template:Cite OEIS</ref> Mertens function zero
1547 = hexagonal pyramidal number
1548 = coreful perfect number<ref name="auto31"/>
1549 = de Polignac prime<ref name="auto67">Template:Cite OEIS</ref>
1550 = <math>\frac {31 \times (3 \times 31 + 7)}{2}</math> = number of cards needed to build a 31-tier house of cards with a flat, one-card-wide roof<ref>Template:Cite OEIS</ref>
1551 = 6920 - 5369 = A169952(24) - A169952(23) = A169942(24) = number of Golomb rulers of length 24<ref>Template:Cite OEIS</ref><ref>Template:Cite OEIS</ref>
1552 = Number of partitions of 57 into prime parts
1553 = 509 + 521 + 523 = a prime that is the sum of three consecutive primes<ref>Template:Cite OEIS</ref>
1554 = 2 × 3 × 7 × 37 = product of four distinct primes<ref>Template:Cite OEIS</ref>
1555² divides 6¹⁵⁵⁴<ref>Template:Cite OEIS</ref>
1556 = sum of the squares of the first nine primes
1557 = number of graphs with 8 nodes and 13 edges<ref name="auto78">Template:Cite OEIS</ref>
1558 = number k such that k⁶⁴ + 1 is prime
1559 = Sophie Germain prime<ref name="Sophie Germain" />
1560 = pronic number<ref name="pronic number" />
1561 = a centered octahedral number,<ref name="auto7"/> number of series-reduced trees with 19 nodes<ref>Template:Cite OEIS</ref>
1562 = maximal number of regions the plane is divided into by drawing 40 circles<ref name="auto27"/>
1563 = <math>\sum_{k=1}^{50} \frac{50}{\gcd(50,k)}</math><ref>Template:Cite OEIS</ref>
1564 = sum of totient function for first 71 integers
1565 = <math>\sqrt{1036^2+1173^2}</math> and <math>1036+1173=47^2</math><ref>Template:Cite OEIS</ref>
1566 = number k such that k⁶⁴ + 1 is prime
1567 = number of partitions of 24 with at least one distinct part<ref name="auto66"/>
1568 = Achilles number<ref name="Achilles">Template:Cite OEIS</ref>
1569 = 2 × 28² + 1 = number of different 2 × 2 determinants with integer entries from 0 to 28<ref name="auto32"/>
1570 = 2 × 28² + 2 = number of points on surface of tetrahedron with edgelength 28<ref name="auto59"/>
1571 = Honaker prime<ref name="auto39"/>
1572 = member of the Mian–Chowla sequence<ref name=Mian-Chowla />
1573 = discriminant of a totally real cubic field<ref name="ReferenceF"/>
1574²⁵⁶ + 1 is prime<ref>Template:Cite OEIS</ref>
1575 = odd abundant number,<ref>{{#invoke:citation/CS1|citation

|CitationClass=web }}</ref> sum of the nontriangular numbers between successive triangular numbers, number of partitions of 24<ref name="auto35"/>

1576¹⁴ == 1 (mod 15^2)<ref>Template:Cite OEIS</ref>
1577 = sum of the quadratic residues of 83<ref>Template:Cite OEIS</ref>
1578 = sum of first 45 composite numbers<ref name="auto94"/>
1579 = number of partitions of 54 such that the smallest part is greater than or equal to number of parts<ref name="auto75"/>
1580 = number of achiral integer partitions of 51<ref name="auto64"/>
1581 = number of edges in the hexagonal triangle T(31)<ref name="auto60"/>
1582 = a number such that the integer triangle [A070080(1582), A070081(1582), A070082(1582)] has an integer area<ref>Template:Cite OEIS</ref>
1583 = Sophie Germain prime
1584 = triangular matchstick number<ref name="auto5"/>
1585 = Riordan number, centered triangular number<ref name="auto52"/>
1586 = area of the 23rd conjoined trapezoid<ref name="auto13"/>
1587 = 3 × 23² = number of edges of a complete tripartite graph of order 69, K_23,23,23<ref>Template:Cite OEIS</ref>
1588 = sum of totient function for first 72 integers
1589 = composite de Polignac number<ref name="auto53"/>
1590 = rounded volume of a regular icosahedron with edge length 9<ref>Template:Cite OEIS</ref>
1591 = rounded volume of a regular octahedron with edge length 15<ref name="auto84"/>
1592 = sum of all divisors of the first 36 odd numbers<ref>Template:Cite OEIS</ref>
1593 = sum of the first 30 primes
1594 = minimal cost of maximum height Huffman tree of size 17<ref>Template:Cite OEIS</ref>
1595 = number of non-isomorphic set-systems of weight 10
1596 = 56th triangular number<ref name="Triangular number" />
1597 = Fibonacci prime,<ref>{{#invoke:citation/CS1|citation

|CitationClass=web }}</ref> Markov prime,<ref name="Markov number" /> super-prime, emirp

1598 = number of unimodular 2 × 2 matrices having all terms in {0,1,...,25}<ref name="auto54"/>
1599 = number of edges in the join of two cycle graphs, both of order 39<ref name="auto89"/>

1600 to 1699Edit

1600 = 40², structured great rhombicosidodecahedral number,<ref>Template:Cite OEIS</ref> repdigit in base 7 (4444₇), street number on Pennsylvania Avenue of the White House, length in meters of a common High School Track Event, perfect score on SAT (except from 2005 to 2015)
1601 = Sophie Germain prime, Proth prime,<ref name="Proth prime" /> the novel 1601 (Mark Twain)
1602 = number of points on surface of octahedron with edgelength 20<ref name="auto61"/>
1603 = number of partitions of 27 with nonnegative rank<ref name="auto18">Template:Cite OEIS</ref>
1604 = number of compositions of 22 into prime parts<ref>Template:Cite OEIS</ref>
1605 = number of polyominoes consisting of 7 regular octagons<ref>Template:Cite OEIS</ref>
1606 = enneagonal pyramidal number<ref>Template:Cite OEIS</ref>
1607 = member of prime triple with 1609 and 1613<ref>Template:Cite OEIS</ref>
1608 = <math>\sum_{k=1}^{44} \sigma(k)</math><ref name="auto38"/>
1609 = cropped hexagonal number<ref name="auto44"/>
1610 = number of strict partions of 43<ref name="auto20"/>
1611 = number of rational numbers which can be constructed from the set of integers between 1 and 51<ref name="auto56"/>
1612 = maximum dimension of Euclidean spaces which suffice for every smooth compact Riemannian 31-manifold to be realizable as a sub-manifold<ref name="ReferenceE"/>
1613, 1607 and 1619 are all primes<ref>Template:Cite OEIS</ref>
1614 = number of ways of refining the partition 8^1 to get 1^8<ref>Template:Cite OEIS</ref>
1615 = composite number such that the square mean of its prime factors is a nonprime integer<ref>Template:Cite OEIS</ref>
1616 = <math>\frac{16(16^2 + 3 \times 16 - 1)}{3}</math> = number of monotonic triples (x,y,z) in {1,2,...,16}³<ref>Template:Cite OEIS</ref>
1617 = pentagonal number<ref name="Pentagonal number" />
1618 = centered heptagonal number<ref name="centered heptagonal number" />
1619 = palindromic prime in binary, safe prime<ref name="Safe primes" />
1620 = 809 + 811: sum of twin prime pair<ref name="auto48"/>
1621 = super-prime, pinwheel number<ref name="Pinwheel" />
1622 = semiprime of the form prime + 1<ref>Template:Cite OEIS</ref>
1623 is not the sum of two triangular numbers and a fourth power<ref>Template:Cite OEIS</ref>
1624 = number of squares in the Aztec diamond of order 28<ref name="auto36">Template:Cite OEIS</ref>
1625 = centered square number<ref name="Centered square numbers" />
1626 = centered pentagonal number<ref name="Centered pentagonal" />
1627 = prime and 2 × 1627 - 1 = 3253 is also prime<ref>Template:Cite OEIS</ref>
1628 = centered pentagonal number<ref name="Centered pentagonal" />
1629 = rounded volume of a regular tetrahedron with edge length 24<ref name="auto88"/>
1630 = number k such that k^64 + 1 is prime
1631 = <math>\sum_{k=0}^{5} (k+1)! \binom{5}{k}</math><ref>Template:Cite OEIS</ref>
1632 = number of acute triangles made from the vertices of a regular 18-polygon<ref>Template:Cite OEIS</ref>
1633 = star number<ref name="Centered 12-gonal numbers" />
1634 = the smallest four-digit Narcissistic number in base 10
1635 = number of partitions of 56 whose reciprocal sum is an integer<ref>Template:Cite OEIS</ref>
1636 = number of nonnegative solutions to x² + y² ≤ 45²<ref name="auto65"/>
1637 = prime island: least prime whose adjacent primes are exactly 30 apart<ref>Template:Cite OEIS</ref>
1638 = harmonic divisor number,<ref>{{#invoke:citation/CS1|citation

|CitationClass=web }}</ref> 5 × 2¹⁶³⁸ - 1 is prime<ref name="auto69"/>

1639 = nonagonal number<ref name="Nonagonal number" />
1640 = pronic number<ref name="pronic number" />
1641 = 41² - 41 + 1 = H₄₁ (the 41st Hogben number)<ref name="auto77"/>
1642 = maximal number of regions the plane is divided into by drawing 41 circles<ref name="auto27"/>
1643 = sum of first 46 composite numbers<ref name="auto94"/>
1644 = 821 + 823: sum of twin prime pair<ref name="auto48"/>
1645 = number of 16-celled pseudo still lifes in Conway's Game of Life, up to rotation and reflection<ref>Template:Cite OEIS</ref>
1646 = number of graphs with 8 nodes and 14 edges<ref name="auto78"/>
1647 and 1648 are both divisible by cubes<ref>Template:Cite OEIS</ref>
1648 = number of partitions of 34³ into distinct cubes<ref>Template:Cite OEIS</ref>
1649 = highly cototient number,<ref name="highly cototient" /> Leyland number<ref name=A076980/> using 4 & 5 (4⁵ + 5⁴)
1650 = number of cards to build an 33-tier house of cards<ref name="auto45"/>
1651 = heptagonal number<ref name="heptagonal number" />
1652 = number of partitions of 29 into a prime number of parts<ref name="auto70"/>
1653 = 57th triangular number,<ref name="Triangular number" /> hexagonal number,<ref name="Hexagonal number" /> number of lattice points inside a circle of radius 23<ref name="auto22"/>
1654 = number of partitions of 42 into divisors of 42<ref>Template:Cite OEIS</ref>
1655 = rounded volume of a regular dodecahedron with edge length 6<ref>Template:Cite OEIS</ref>
1656 = 827 + 829: sum of twin prime pair<ref name="auto48"/>
1657 = cuban prime,<ref name="Cuban Prime">{{#invoke:citation/CS1|citation

|CitationClass=web }}</ref> prime of the form 2p-1

1658 = smallest composite that when added to sum of prime factors reaches a prime after 25 iterations<ref name="auto37"/>
1659 = number of rational numbers which can be constructed from the set of integers between 1 and 52<ref name="auto56"/>
1660 = sum of totient function for first 73 integers
1661 = 11 × 151, palindrome that is a product of two palindromic primes<ref name="auto29"/>
1662 = number of partitions of 49 into pairwise relatively prime parts<ref name="auto71"/>
1663 = a prime number and 5¹⁶⁶³ - 4¹⁶⁶³ is a 1163-digit prime number<ref>Template:Cite OEIS</ref>
1664 = k such that k, k+1 and k+2 are sums of 2 squares<ref name="auto97">Template:Cite OEIS</ref>
1665 = centered tetrahedral number<ref name="auto42"/>
1666 = largest efficient pandigital number in Roman numerals (each symbol occurs exactly once)
1667 = 228 + 1439 and the 228th prime is 1439<ref name="auto47"/>
1668 = number of partitions of 33 into parts all relatively prime to 33<ref>Template:Cite OEIS</ref>
1669 = super-prime, smallest prime with a gap of exactly 24 to the next prime<ref>Template:Cite OEIS</ref>
1670 = number of compositions of 12 such that at least two adjacent parts are equal<ref>Template:Cite OEIS</ref>
1671 divides the sum of the first 1671 composite numbers<ref>Template:Cite OEIS</ref>
1672 = 41² - 3², the only way to express 1672 as a difference of prime squares<ref name="auto96"/>
1673 = RMS number<ref>Template:Cite OEIS</ref>
1674 = k such that geometric mean of phi(k) and sigma(k) is an integer<ref name="auto68"/>
1675 = Kin number<ref>Template:Cite OEIS</ref>
1676 = number of partitions of 34 into parts each of which is used a different number of times<ref name="ReferenceG"/>
1677 = 41² - 2², the only way to express 1677 as a difference of prime squares<ref name="auto96"/>
1678 = n such that n³² + 1 is prime<ref name="auto51"/>
1679 = highly cototient number,<ref name="highly cototient" /> semiprime (23 × 73, see also Arecibo message), number of parts in all partitions of 32 into distinct parts<ref name="auto46"/>
1680 = the 17th highly composite number,<ref name="Highly composite" /> number of edges in the join of two cycle graphs, both of order 40<ref name="auto89"/>
1681 = 41², smallest number yielded by the formula n² + n + 41 that is not a prime; centered octagonal number<ref name="Centered octagonal number" />
1682 = and 1683 is a member of a Ruth–Aaron pair (first definition)
1683 = triangular matchstick number<ref name="auto5"/>
1684 = centered triangular number<ref name="auto52"/>
1685 = 5-Knödel number<ref name="auto14"/>
1686 = <math>\sum_{k=1}^{45} \sigma(k)</math><ref name="auto38"/>
1687 = 7-Knödel number<ref name="auto21"/>
1688 = number of finite connected sets of positive integers greater than one with least common multiple 72<ref>Template:Cite OEIS</ref>
1689 = <math>9!!\sum_{k=0}^{4} \frac{1}{2k+1}</math><ref>Template:Cite OEIS</ref>
1690 = number of compositions of 14 into powers of 2<ref>Template:Cite OEIS</ref>
1691 = the same upside down, which makes it a strobogrammatic number<ref>Template:Cite OEIS</ref>
1692 = coreful perfect number<ref name="auto31"/>
1693 = smallest prime > 41².<ref name="auto57"/>
1694 = number of unimodular 2 × 2 matrices having all terms in {0,1,...,26}<ref name="auto54"/>
1695 = magic constant of n × n normal magic square and n-queens problem for n = 15. Number of partitions of 58 into prime parts
1696 = sum of totient function for first 74 integers
1697 = Friedlander-Iwaniec prime<ref name="auto12"/>
1698 = number of rooted trees with 47 vertices in which vertices at the same level have the same degree<ref name="auto28"/>
1699 = number of rooted trees with 48 vertices in which vertices at the same level have the same degree<ref name="auto28"/>

1700 to 1799Edit

1700 = σ₂(39): sum of squares of divisors of 39<ref name="auto76"/>
1701 = <math>\left\{ {8 \atop 4} \right\}</math>, decagonal number, hull number of the U.S.S. Enterprise on Star Trek
1702 = palindromic in 3 consecutive bases: 898₁₄, 787₁₅, 6A6₁₆
1703 = 1703131131 / 1000077 and the divisors of 1703 are 1703, 131, 13 and 1<ref>Template:Cite OEIS</ref>
1704 = sum of the squares of the parts in the partitions of 18 into two distinct parts<ref>Template:Cite OEIS</ref>
1705 = tribonacci number<ref>{{#invoke:citation/CS1|citation

|CitationClass=web }}</ref>

1706 = 1 + 4 + 16 + 64 + 256 + 1024 + 256 + 64 + 16 + 4 + 1 sum of fifth row of triangle of powers of 4<ref>Template:Cite OEIS</ref>
1707 = number of partitions of 30 in which the number of parts divides 30<ref name="auto63"/>
1708 = 2² × 7 × 61 a number whose product of prime indices 1 × 1 × 4 × 18 is divisible by its sum of prime factors 2 + 2 + 7 + 61<ref>Template:Cite OEIS</ref>
1709 = first of a sequence of eight primes formed by adding 57 in the middle. 1709, 175709, 17575709, 1757575709, 175757575709, 17575757575709, 1757575757575709 and 175757575757575709 are all prime, but 17575757575757575709 = 232433 × 75616446785773
1710 = maximal number of pieces that can be obtained by cutting an annulus with 57 cuts<ref name="auto73"/>
1711 = 58th triangular number,<ref name="Triangular number" /> centered decagonal number
1712 = number of irredundant sets in the 29-cocktail party graph<ref name="auto34"/>
1713 = number of aperiodic rooted trees with 12 nodes<ref>Template:Cite OEIS</ref>
1714 = number of regions formed by drawing the line segments connecting any two of the 18 perimeter points of an 3 × 6 grid of squares<ref>Template:Cite OEIS</ref>
1715 = k such that geometric mean of phi(k) and sigma(k) is an integer<ref name="auto68"/>
1716 = 857 + 859: sum of twin prime pair<ref name="auto48"/>
1717 = pentagonal number<ref name="Pentagonal number" />
1718 = <math>\sum_{d|12} \binom{12}{d}</math><ref>Template:Cite OEIS</ref>
1719 = composite de Polignac number<ref name="auto53"/>
1720 = sum of the first 31 primes
1721 = twin prime; number of squares between 42² and 42⁴.<ref name="auto40"/>
1722 = Giuga number,<ref>{{#invoke:citation/CS1|citation

|CitationClass=web }}</ref> pronic number<ref name="pronic number" />

1723 = super-prime
1724 = maximal number of regions the plane is divided into by drawing 42 circles<ref name="auto27"/>
1725 = 47² - 22² = (prime(15))² - (nonprime(15))²<ref>Template:Cite OEIS</ref>
1726 = number of partitions of 44 into distinct and relatively prime parts<ref>Template:Cite OEIS</ref>
1727 = area of the 24th conjoined trapezoid<ref name="auto13"/>
1728 = the quantity expressed as 1000 in duodecimal, that is, the cube of twelve (called a great gross), and so, the number of cubic inches in a cubic foot, palindromic in base 11 (1331₁₁) and 23 (363₂₃)
1729 = taxicab number, Carmichael number, Zeisel number, centered cube number, Hardy–Ramanujan number. In the decimal expansion of e the first time all 10 digits appear in sequence starts at the 1729th digit (or 1728th decimal place). In 1979 the rock musical Hair closed on Broadway in New York City after 1729 performances. Palindromic in bases 12, 32, 36.
1730 = 3 × 24² + 2 = number of points on surface of square pyramid of side-length 24<ref name="auto58"/>
1731 = k such that geometric mean of phi(k) and sigma(k) is an integer<ref name="auto68"/>
1732 = <math>\sum_{k=0}^5 \binom{5}{k}^k</math><ref>Template:Cite OEIS</ref>
1733 = Sophie Germain prime, palindromic in bases 3, 18, 19.
1734 = surface area of a cube of edge length 17<ref>Template:Cite OEIS</ref>
1735 = number of partitions of 55 such that the smallest part is greater than or equal to number of parts<ref name="auto75"/>
1736 = sum of totient function for first 75 integers, number of surface points on a cube with edge-length 18<ref name="A005897" />
1737 = pinwheel number<ref name="Pinwheel" />
1738 = number of achiral integer partitions of 52<ref name="auto64"/>
1739 = number of 1s in all partitions of 30 into odd parts<ref>Template:Cite OEIS</ref>
1740 = number of squares in the Aztec diamond of order 29<ref name="auto36"/>
1741 = super-prime, centered square number<ref name="Centered square numbers" />
1742 = number of regions the plane is divided into by 30 ellipses<ref name="auto91"/>
1743 = wiener index of the windmill graph D(3,21)<ref name="auto90"/>
1744 = k such that k, k+1 and k+2 are sums of 2 squares<ref name="auto97"/>
1745 = 5-Knödel number<ref name="auto14"/>
1746 = number of unit-distance graphs on 8 nodes<ref>Template:Cite OEIS</ref>
1747 = balanced prime<ref name="Balanced prime" />
1748 = number of partitions of 55 into distinct parts in which the number of parts divides 55<ref>Template:Cite OEIS</ref>
1749 = number of integer partitions of 33 with no part dividing all the others<ref name="auto30"/>
1750 = hypotenuse in three different Pythagorean triangles<ref name="auto101"/>
1751 = cropped hexagone<ref name="auto44"/>
1752 = 79² - 67², the only way to express 1752 as a difference of prime squares<ref name="auto96"/>
1753 = balanced prime<ref name="Balanced prime" />
1754 = k such that 5*2^k - 1 is prime<ref name="auto69"/>
1755 = number of integer partitions of 50 whose augmented differences are distinct<ref name="auto19"/>
1756 = centered pentagonal number<ref name="Centered pentagonal" />
1757 = least number of triangles of the Spiral of Theodorus to complete 13 revolutions<ref name="auto85"/>
1758 = <math>\sum_{k=1}^{46} \sigma(k)</math><ref name="auto38"/>
1759 = de Polignac prime<ref name="auto67"/>
1760 = the number of yards in a mile
1761 = k such that k, k+1 and k+2 are products of two primes<ref name="auto81"/>
1762 = number of binary sequences of length 12 and curling number 2<ref>Template:Cite OEIS</ref>
1763 = number of edges in the join of two cycle graphs, both of order 41<ref name="auto89"/>
1764 = 42²
1765 = number of stacks, or planar partitions of 15<ref>Template:Cite OEIS</ref>
1766 = number of points on surface of octahedron with edge length 21<ref name="auto61"/>
1767 = σ(28²) = σ(35²)<ref>Template:Cite OEIS</ref>
1768 = number of nonequivalent dissections of an hendecagon into 8 polygons by nonintersecting diagonals up to rotation<ref>Template:Cite OEIS</ref>
1769 = maximal number of pieces that can be obtained by cutting an annulus with 58 cuts<ref name="auto73"/>
1770 = 59th triangular number,<ref name="Triangular number" /> hexagonal number,<ref name="Hexagonal number" /> Seventeen Seventy, town in Australia
1771 = tetrahedral number<ref name="Tetrahedral nu"/>
1772 = centered heptagonal number,<ref name="centered heptagonal number" /> sum of totient function for first 76 integers
1773 = number of words of length 5 over the alphabet {1,2,3,4,5} such that no two even numbers appear consecutively<ref>Template:Cite OEIS</ref>
1774 = number of rooted identity trees with 15 nodes and 5 leaves<ref>Template:Cite OEIS</ref>
1775 = <math>\sum_{1\leq i\leq 10}prime(i)\cdot(2\cdot i-1)</math>: sum of piles of first 10 primes<ref>Template:Cite OEIS</ref>
1776 = 24th square star number.<ref>Template:Cite OEIS</ref> The number of pieces that could be seen in a 7 × 7 × 7× 7 Rubik's Tesseract.
1777 = smallest prime > 42².<ref name="auto57"/>
1778 = least k >= 1 such that the remainder when 6^k is divided by k is 22<ref>Template:Cite OEIS</ref>
1779 = number of achiral integer partitions of 53<ref name="auto64"/>
1780 = number of lattice paths from (0, 0) to (7, 7) using E (1, 0) and N (0, 1) as steps that horizontally cross the diagonal y = x with even many times<ref>Template:Cite OEIS</ref>
1781 = the first 1781 digits of e form a prime<ref>Template:Cite OEIS</ref>
1782 = heptagonal number<ref name="heptagonal number" />
1783 = de Polignac prime<ref name="auto67"/>
1784 = number of subsets of {1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12} such that every pair of distinct elements has a different quotient<ref>Template:Cite OEIS</ref>
1785 = square pyramidal number,<ref name="Square pyramidal numbers" /> triangular matchstick number<ref name="auto5"/>
1786 = centered triangular number<ref name="auto52"/>
1787 = super-prime, sum of eleven consecutive primes (137 + 139 + 149 + 151 + 157 + 163 + 167 + 173 + 179 + 181 + 191)
1788 = Euler transform of -1, -2, ..., -34<ref>Template:Cite OEIS</ref>
1789 = number of wiggly sums adding to 17 (terms alternately increase and decrease or vice versa)<ref>Template:Cite OEIS</ref>
1790 = number of partitions of 50 into pairwise relatively prime parts<ref name="auto71"/>
1791 = largest natural number that cannot be expressed as a sum of at most four hexagonal numbers.
1792 = Granville number
1793 = number of lattice points inside a circle of radius 24<ref name="auto22"/>
1794 = nonagonal number,<ref name="Nonagonal number" /> number of partitions of 33 that do not contain 1 as a part<ref name="auto8"/>
1795 = number of heptagons with perimeter 38<ref>Template:Cite OEIS</ref>
1796 = k such that geometric mean of phi(k) and sigma(k) is an integer<ref name="auto68"/>
1797 = number k such that phi(prime(k)) is a square<ref name="auto55"/>
1798 = 2 × 29 × 31 = 10₂ × 11101₂ × 11111₂, which yield zero when the prime factors are xored together<ref>Template:Cite OEIS</ref>
1799 = 2 × 30² − 1 = a twin square<ref name="auto83"/>

1800 to 1899Edit

1800 = pentagonal pyramidal number,<ref name="Pentagonal pyramidal number" /> Achilles number, also, in da Ponte's Don Giovanni, the number of women Don Giovanni had slept with so far when confronted by Donna Elvira, according to Leporello's tally
1801 = cuban prime, sum of five and nine consecutive primes (349 + 353 + 359 + 367 + 373 and 179 + 181 + 191 + 193 + 197 + 199 + 211 + 223 + 227)<ref name="Cuban Prime" />
1802 = 2 × 30² + 2 = number of points on surface of tetrahedron with edge length 30,<ref name="auto59"/> number of partitions of 30 such that the number of odd parts is a part<ref name="auto72"/>
1803 = number of decahexes that tile the plane isohedrally but not by translation or by 180-degree rotation (Conway criterion)<ref>Template:Cite OEIS</ref>
1804 = number k such that k^64 + 1 is prime
1805 = number of squares between 43² and 43⁴.<ref name="auto40"/>
1806 = pronic number,<ref name="pronic number" /> product of first four terms of Sylvester's sequence, primary pseudoperfect number,<ref>{{#invoke:citation/CS1|citation

|CitationClass=web }}</ref> only number for which n equals the denominator of the nth Bernoulli number,<ref>Kellner, Bernard C.; 'The equation denom(B_n) = n has only one solution'</ref> Schröder number<ref>Template:Cite OEIS</ref>

1807 = fifth term of Sylvester's sequence<ref>{{#invoke:citation/CS1|citation

|CitationClass=web }}</ref>

1808 = maximal number of regions the plane is divided into by drawing 43 circles<ref name="auto27"/>
1809 = sum of first 17 super-primes<ref>Template:Cite OEIS</ref>
1810 = <math>\sum_{k=0}^4 \binom{4}{k}^4</math><ref>Template:Cite OEIS</ref>
1811 = Sophie Germain prime
1812 = n such that n³² + 1 is prime<ref name="auto51"/>
1813 = number of polyominoes with 26 cells, symmetric about two orthogonal axes<ref>Template:Cite OEIS</ref>
1814 = 1 + 6 + 36 + 216 + 1296 + 216 + 36 + 6 + 1 = sum of 4th row of triangle of powers of six<ref>Template:Cite OEIS</ref>
1815 = polygonal chain number <math>\#(P^3_{2,1})</math><ref>Template:Cite OEIS</ref>
1816 = number of strict partions of 44<ref name="auto20"/>
1817 = total number of prime parts in all partitions of 20<ref>Template:Cite OEIS</ref>
1818 = n such that n³² + 1 is prime<ref name="auto51"/>
1819 = sum of the first 32 primes, minus 32<ref>Template:Cite OEIS</ref>
1820 = pentagonal number,<ref name="Pentagonal number" /> pentatope number,<ref name="Pentatope number" /> number of compositions of 13 whose run-lengths are either weakly increasing or weakly decreasing<ref name="auto1">Template:Cite OEIS</ref>
1821 = member of the Mian–Chowla sequence<ref name=Mian-Chowla />
1822 = number of integer partitions of 43 whose distinct parts are connected<ref name="auto86"/>
1823 = super-prime, safe prime<ref name="Safe primes" />
1824 = 43² - 5², the only way to express 1824 as a difference of prime squares<ref name="auto96"/>
1825 = octagonal number<ref name="auto17"/>
1826 = decagonal pyramidal number<ref name="auto62"/>
1827 = vampire number<ref name="Vampire number" />
1828 = meandric number, open meandric number, appears twice in the first 10 decimal digits of e
1829 = composite de Polignac number<ref name="auto53"/>
1830 = 60th triangular number<ref name="Triangular number" />
1831 = smallest prime with a gap of exactly 16 to next prime (1847)<ref>Template:Cite OEIS</ref>
1832 = sum of totient function for first 77 integers
1833 = number of atoms in a decahedron with 13 shells<ref>Template:Cite OEIS</ref>
1834 = octahedral number,<ref name="Octahedral number" /> sum of the cubes of the first five primes
1835 = absolute value of numerator of <math>D_6^{(5)}</math><ref>Template:Cite OEIS</ref>
1836 = factor by which a proton is more massive than an electron
1837 = star number<ref name="Centered 12-gonal numbers" />
1838 = number of unimodular 2 × 2 matrices having all terms in {0,1,...,27}<ref name="auto54"/>
1839 = <math>\lfloor \sqrt[3]{13!} \rfloor </math><ref>Template:Cite OEIS</ref>
1840 = 43² - 3², the only way to express 1840 as a difference of prime squares<ref name="auto96"/>
1841 = solution to the postage stamp problem with 3 denominations and 29 stamps,<ref>Template:Cite OEIS</ref> Mertens function zero
1842 = number of unlabeled rooted trees with 11 nodes<ref>Template:Cite OEIS</ref>
1843 = k such that phi(k) is a perfect cube,<ref>Template:Cite OEIS</ref> Mertens function zero
1844 = 3⁷ - 7³,<ref>Template:Cite OEIS</ref> Mertens function zero
1845 = number of partitions of 25 containing at least one prime,<ref>Template:Cite OEIS</ref> Mertens function zero
1846 = sum of first 49 composite numbers<ref name="auto94"/>
1847 = super-prime
1848 = number of edges in the join of two cycle graphs, both of order 42<ref name="auto89"/>
1849 = 43², palindromic in base 6 (= 12321₆), centered octagonal number<ref name="Centered octagonal number" />
1850 = Number of partitions of 59 into prime parts
1851 = sum of the first 32 primes
1852 = number of quantales on 5 elements, up to isomorphism<ref>Template:Cite OEIS</ref>
1853 = sum of primitive roots of 27-th prime,<ref>Template:Cite OEIS</ref> Mertens function zero
1854 = number of permutations of 7 elements with no fixed points,<ref>Template:Cite OEIS</ref> Mertens function zero
1855 = rencontres number: number of permutations of [7] with exactly one fixed point<ref>Template:Cite OEIS</ref>
1856 = sum of totient function for first 78 integers
1857 = Mertens function zero, pinwheel number<ref name="Pinwheel" />
1858 = number of 14-carbon alkanes C₁₄H₃₀ ignoring stereoisomers<ref>Template:Cite OEIS</ref>
1859 = composite de Polignac number<ref name="auto53"/>
1860 = number of squares in the Aztec diamond of order 30<ref>{{#invoke:citation/CS1|citation

|CitationClass=web }}</ref>

1861 = centered square number,<ref name="Centered square numbers" /> Mertens function zero
1862 = Mertens function zero, forms a Ruth–Aaron pair with 1863 under second definition
1863 = Mertens function zero, forms a Ruth–Aaron pair with 1862 under second definition
1864 = Mertens function zero, <math>\frac{1864!-2}{2}</math> is a prime<ref>Template:Cite OEIS</ref>
1865 = 12345₆: Largest senary metadrome (number with digits in strict ascending order in base 6)<ref>Template:Cite OEIS</ref>
1866 = Mertens function zero, number of plane partitions of 16 with at most two rows<ref>Template:Cite OEIS</ref>
1867 = prime de Polignac number<ref name="auto67"/>
1868 = smallest number of complexity 21: smallest number requiring 21 1's to build using +, * and ^<ref name="auto49"/>
1869 = Hultman number: S_H(7, 4)<ref>Template:Cite OEIS</ref>
1870 = decagonal number<ref name="Decagonal" />
1871 = the first prime of the 2 consecutive twin prime pairs: (1871, 1873) and (1877, 1879)<ref>Template:Cite OEIS</ref>
1872 = first Zagreb index of the complete graph K₁₃<ref name="auto100"/>
1873 = number of Narayana's cows and calves after 21 years<ref name="auto98"/>
1874 = area of the 25th conjoined trapezoid<ref name="auto13"/>
1875 = 50² - 25²
1876 = number k such that k^64 + 1 is prime
1877 = number of partitions of 39 where 39 divides the product of the parts<ref>Template:Cite OEIS</ref>
1878 = n such that n³² + 1 is prime<ref name="auto51"/>
1879 = a prime with square index<ref>Template:Cite OEIS</ref>
1880 = the 10th element of the self convolution of Lucas numbers<ref>Template:Cite OEIS</ref>
1881 = tricapped prism number<ref>Template:Cite OEIS</ref>
1882 = number of linearly separable Boolean functions in 4 variables<ref>Template:Cite OEIS</ref>
1883 = number of conjugacy classes in the alternating group A₂₈<ref name="auto33"/>
1884 = k such that 5*2^k - 1 is prime<ref name="auto69"/>
1885 = Zeisel number<ref name="Zeisel number" />
1886 = number of partitions of 6⁴ into fourth powers<ref>Template:Cite OEIS</ref>
1887 = number of edges in the hexagonal triangle T(34)<ref name="auto60"/>
1888 = primitive abundant number (abundant number all of whose proper divisors are deficient numbers)<ref name="auto92"/>
1889 = Sophie Germain prime, highly cototient number<ref name="highly cototient" />
1890 = triangular matchstick number<ref name="auto5"/>
1891 = 61st triangular number,<ref name="Triangular number" /> sum of 5 consecutive primes (Template:Math) hexagonal number,<ref name="Hexagonal number" /> centered pentagonal number,<ref name="Centered pentagonal" /> centered triangular number<ref name="auto52"/>
1892 = pronic number<ref name="pronic number" />
1893 = 44² - 44 + 1 = H₄₄ (the 44th Hogben number)<ref name="auto77"/>
1894 = maximal number of regions the plane is divided into by drawing 44 circles<ref name="auto27"/>
1895 = Stern-Jacobsthal number<ref name="auto15"/>
1896 = member of the Mian-Chowla sequence<ref name=Mian-Chowla />
1897 = member of Padovan sequence,<ref name="Padovan sequence" /> number of triangle-free graphs on 9 vertices<ref>Template:Cite OEIS</ref>
1898 = smallest multiple of n whose digits sum to 26<ref>Template:Cite OEIS</ref>
1899 = cropped hexagone<ref name="auto44"/>

1900 to 1999Edit

1900 = number of primes <= 2¹⁴<ref name="auto3"/>
1901 = Sophie Germain prime, centered decagonal number
1902 = number of symmetric plane partitions of 27<ref>Template:Cite OEIS</ref>
1903 = generalized Catalan number<ref>Template:Cite OEIS</ref>
1904 = number of flat partitions of 43<ref name="auto26"/>
1905 = Fermat pseudoprime<ref name="auto93"/>
1906 = number n such that 3ⁿ - 8 is prime<ref>Template:Cite OEIS</ref>
1907 = safe prime,<ref name="Safe primes" /> balanced prime<ref name="Balanced prime" />
1908 = coreful perfect number<ref name="auto31"/>
1909 = hyperperfect number<ref>{{#invoke:citation/CS1|citation

|CitationClass=web }}</ref>

1910 = number of compositions of 13 having exactly one fixed point<ref>Template:Cite OEIS</ref>
1911 = heptagonal pyramidal number<ref name="auto82"/>
1912 = size of 6th maximum raising after one blind in pot-limit poker<ref>Template:Cite OEIS</ref>
1913 = super-prime, Honaker prime<ref name="auto39"/>
1914 = number of bipartite partitions of 12 white objects and 3 black ones<ref>Template:Cite OEIS</ref>
1915 = number of nonisomorphic semigroups of order 5<ref>Template:Cite OEIS</ref>
1916 = sum of first 50 composite numbers<ref name="auto94"/>
1917 = number of partitions of 51 into pairwise relatively prime parts<ref name="auto71"/>
1918 = heptagonal number<ref name="heptagonal number" />
1919 = smallest number with reciprocal of period length 36 in base 10<ref>Template:Cite OEIS</ref>
1920 = sum of the nontriangular numbers between successive triangular numbers 120 and 136,
1921 = 4-dimensional centered cube number<ref>Template:Cite OEIS</ref>
1922 = Area of a square with diagonal 62<ref name="area of a square with diagonal 2n"/>
1923 = 2 × 31² + 1 = number of different 2 X 2 determinants with integer entries from 0 to 31<ref name="auto32"/>
1924 = 2 × 31² + 2 = number of points on surface of tetrahedron with edge length 31,<ref name="auto59"/> sum of the first 36 semiprimes<ref>Template:Cite OEIS</ref>
1925 = number of ways to write 24 as an orderless product of orderless sums<ref name="auto79"/>
1926 = pentagonal number<ref name="Pentagonal number" />
1927 = 2¹¹ - 11²<ref>Template:Cite OEIS</ref>
1928 = number of distinct values taken by 2^2^...^2 (with 13 2's and parentheses inserted in all possible ways)<ref>Template:Cite OEIS</ref>
1929 = Mertens function zero, number of integer partitions of 42 whose distinct parts are connected<ref name="auto86"/>
1930 = number of pairs of consecutive integers x, x+1 such that all prime factors of both x and x+1 are at most 53<ref name="auto80"/>
1931 = Sophie Germain prime
1932 = number of partitions of 40 into prime power parts<ref name="auto87"/>
1933 = centered heptagonal number,<ref name="centered heptagonal number" /> Honaker prime<ref name="auto39"/>
1934 = sum of totient function for first 79 integers
1935 = number of edges in the join of two cycle graphs, both of order 43<ref name="auto89"/>
1936 = 44², 18-gonal number,<ref>{{#invoke:citation/CS1|citation

|CitationClass=web }}</ref> 324-gonal number.

1937 = number of chiral n-ominoes in 12-space, one cell labeled<ref>Template:Cite OEIS</ref>
1938 = Mertens function zero, number of points on surface of octahedron with edge length 22<ref name="auto61"/>
1939 = 7-Knödel number<ref name="auto21"/>
1940 = the Mahonian number: T(8, 9)<ref name="A008302" />
1941 = maximal number of regions obtained by joining 16 points around a circle by straight lines<ref>Template:Cite OEIS</ref>
1942 = number k for which 10k + 1, 10k + 3, 10k + 7, 10k + 9 and 10k + 13 are primes<ref>Template:Cite OEIS</ref>
1943 = largest number not the sum of distinct tetradecagonal numbers<ref name="auto24">Template:Cite OEIS</ref>
1944 = 3-smooth number (2³×3⁵), Achilles number<ref name="Achilles" />
1945 = number of partitions of 25 into relatively prime parts such that multiplicities of parts are also relatively prime<ref>Template:Cite OEIS</ref>
1946 = number of surface points on a cube with edge-length 19<ref name="A005897" />
1947 = k such that 5·2^k + 1 is a prime factor of a Fermat number 2^{2^m} + 1 for some m<ref>Template:Cite OEIS</ref>
1948 = number of strict solid partitions of 20<ref name="auto43"/>
1949 = smallest prime > 44².<ref name="auto57"/>
1950 = <math>1 \cdot 2 \cdot 3 + 4 \cdot 5 \cdot 6 + 7 \cdot 8 \cdot 9 + 10 \cdot 11 \cdot 12</math>,<ref>Template:Cite OEIS</ref> largest number not the sum of distinct pentadecagonal numbers<ref name="auto24"/>
1951 = cuban prime<ref name="Cuban Prime" />
1952 = number of covers of {1, 2, 3, 4}<ref>Template:Cite OEIS</ref>
1953 = hexagonal prism number,<ref>Template:Cite OEIS</ref> 62nd triangular number<ref name="Triangular number" />
1954 = number of sum-free subsets of {1, ..., 16}<ref name="auto41"/>
1955 = number of partitions of 25 with at least one distinct part<ref name="auto66"/>
1956 = nonagonal number<ref name="Nonagonal number" />
1957 = <math>\sum_{k=0}^{6} \frac{6!}{k!}</math> = total number of ordered k-tuples (k=0,1,2,3,4,5,6) of distinct elements from an 6-element set<ref>Template:Cite OEIS</ref>
1958 = number of partitions of 25<ref name="auto35"/>
1959 = Heptanacci-Lucas number<ref>Template:Cite OEIS</ref>
1960 = number of parts in all partitions of 33 into distinct parts<ref name="auto46"/>
1961 = number of lattice points inside a circle of radius 25<ref name="auto22"/>
1962 = number of edges in the join of the complete graph K₃₆ and the cycle graph C₃₆<ref>Template:Cite OEIS</ref>
1963! - 1 is prime<ref>Template:Cite OEIS</ref>
1964 = number of linear forests of planted planar trees with 8 nodes<ref>Template:Cite OEIS</ref>
1965 = total number of parts in all partitions of 17<ref name="auto16"/>
1966 = sum of totient function for first 80 integers
1967 = least edge-length of a square dissectable into at least 30 squares in the Mrs. Perkins's quilt problem<ref>Template:Cite OEIS</ref>
σ(1968) = σ(1967) + σ(1966)<ref>Template:Cite OEIS</ref>
1969 = Only value less than four million for which a "mod-ification" of the standard Ackermann Function does not stabilize<ref>Template:Cite journal</ref>
1970 = number of compositions of two types of 9 having no even parts<ref>Template:Cite OEIS</ref>
1971 = <math>3^7-6^3</math><ref>Template:Cite OEIS</ref>
1972 = n such that <math>\frac{n^{37}-1}{n-1}</math> is prime<ref>Template:Cite OEIS</ref>
Template:Anchor 1973 = Sophie Germain prime, Leonardo prime
1974 = number of binary vectors of length 17 containing no singletons<ref name="auto50"/>
1975 = number of partitions of 28 with nonnegative rank<ref name="auto18"/>
1976 = octagonal number<ref name="auto17"/>
1977 = number of non-isomorphic multiset partitions of weight 9 with no singletons<ref>Template:Cite OEIS</ref>
1978 = n such that n | (3ⁿ + 5)<ref>Template:Cite OEIS</ref>
1979 = number of squares between 45² and 45⁴,<ref name="auto40"/> smallest number that is the sum of 4 positive cubes in at least 4 ways<ref>Template:Cite OEIS</ref>
1980 = pronic number,<ref name="pronic number" /> highly abundant number with a greater sum of proper divisors than all smaller numbers<ref>Template:Cite OEIS</ref>
1981 = pinwheel number,<ref name="Pinwheel" /> central polygonal number<ref name="auto11"/>
1982 = maximal number of regions the plane is divided into by drawing 45 circles,<ref name="auto27"/> a number with the property that 3¹⁹⁸² - 1982 is prime<ref>Template:Cite OEIS</ref>
1983 = skiponacci number<ref name="auto25"/>
1984 = 11111000000 in binary, nonunitary perfect number,<ref>Template:Cite OEIS</ref> see also: 1984 (disambiguation)
1985 = centered square number<ref name="Centered square numbers" />
1986 = number of ways to write 25 as an orderless product of orderless sums<ref name="auto79"/>
1987 = 300th prime number
1988 = sum of the first 33 primes,<ref>Template:Cite OEIS</ref> sum of the first 51 composite numbers<ref>Template:Cite OEIS</ref>
1989 = number of balanced primes less than 100,000,<ref>Template:Cite OEIS</ref> number of 9-step mappings with 4 inputs<ref name="auto95"/>
1990 = Stella octangula number
1991 = 11 × 181, the 46th Gullwing number,<ref>Template:Cite OEIS</ref> palindromic composite number with only palindromic prime factors<ref>Template:Cite OEIS</ref>
1992 = number of nonisomorphic sets of nonempty subsets of a 4-set<ref>Template:Cite OEIS</ref>
1993 = a number with the property that 4¹⁹⁹³ - 3¹⁹⁹³ is prime,<ref>Template:Oeis</ref> number of partitions of 30 into a prime number of parts<ref name="auto70"/>
1994 = Glaisher's function W(37)<ref>Template:Cite OEIS</ref>
1995 = number of unlabeled graphs on 9 vertices with independence number 6<ref>Template:Cite OEIS</ref>
1996 = a number with the property that (1996! + 3)/3 is prime<ref>Template:Cite OEIS</ref>
1997 = <math>\sum_{k=1}^{21} {k \cdot \phi(k)}</math><ref>Template:Cite OEIS</ref>
1998 = triangular matchstick number<ref name="auto5"/>
1999 = centered triangular number,<ref>Template:Cite OEIS</ref> number of regular forms in a myriagram.

Prime numbersEdit

There are 135 prime numbers between 1000 and 2000:<ref>Template:Cite OEIS</ref><ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>

1009, 1013, 1019, 1021, 1031, 1033, 1039, 1049, 1051, 1061, 1063, 1069, 1087, 1091, 1093, 1097, 1103, 1109, 1117, 1123, 1129, 1151, 1153, 1163, 1171, 1181, 1187, 1193, 1201, 1213, 1217, 1223, 1229, 1231, 1237, 1249, 1259, 1277, 1279, 1283, 1289, 1291, 1297, 1301, 1303, 1307, 1319, 1321, 1327, 1361, 1367, 1373, 1381, 1399, 1409, 1423, 1427, 1429, 1433, 1439, 1447, 1451, 1453, 1459, 1471, 1481, 1483, 1487, 1489, 1493, 1499, 1511, 1523, 1531, 1543, 1549, 1553, 1559, 1567, 1571, 1579, 1583, 1597, 1601, 1607, 1609, 1613, 1619, 1621, 1627, 1637, 1657, 1663, 1667, 1669, 1693, 1697, 1699, 1709, 1721, 1723, 1733, 1741, 1747, 1753, 1759, 1777, 1783, 1787, 1789, 1801, 1811, 1823, 1831, 1847, 1861, 1867, 1871, 1873, 1877, 1879, 1889, 1901, 1907, 1913, 1931, 1933, 1949, 1951, 1973, 1979, 1987, 1993, 1997, 1999

NotesEdit

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ReferencesEdit

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