43 (number)

43 (forty-three) is the natural number following 42 and preceding 44.

Mathematics

43 is a prime number, and a twin prime of 41. 43 is the smallest prime that is not a Chen prime. 43 is also a Wagstaff prime,<ref>Template:Cite OEIS</ref> and a Heegner number.<ref>Template:Cite OEIS</ref> 43 is the fourth term of Sylvester's sequence.<ref>Template:Cite OEIS</ref>

43 is the largest prime which divides the order of the Janko group J₄.

Dutch mathematician Hendrik Lenstra wrote a mathematical research paper discussing the properties of the number, titled Ode to the number 43.

File:SriYantra color.svg

The Sri Yantra, with nine interlocking triangles that collectively form 43 smaller triangles

Notes

Further reading

Lenstra, Hendrik (2009). Ode to the number 43 (In Dutch). Nieuw Arch. Wiskd. Amsterdam, NL: Koninklijk Wiskundig Genootschap (5) 10, No. 4: 240-244. Template:MR Template:Zbl