Editing Semiperfect number (section)

{{Short description|Number equal to the sum of some of its divisors}}
{{Infobox integer sequence
| image = Perfect number Cuisenaire rods 6 exact.svg
| image_size = 250px
| caption = <small>Demonstration, with [[Cuisenaire rods]], of the perfection of the number 6.</small>
| number = [[infinity]]
| first_terms = [[6 (number)|6]], [[12 (number)|12]], [[18 (number)|18]], [[20 (number)|20]], [[24 (number)|24]], [[28 (number)|28]], [[30 (number)|30]]
| OEIS = A005835
| OEIS_name = Pseudoperfect (or semiperfect) numbers
}}
In [[number theory]], a '''semiperfect number''' or '''pseudoperfect number''' is a [[natural number]] ''n'' that is equal to the sum of all or some of its [[proper divisor]]s. A semiperfect number that is equal to the sum of all its proper divisors is a [[perfect number]].

The first few semiperfect numbers are: [[6 (number)|6]], [[12 (number)|12]], [[18 (number)|18]], [[20 (number)|20]], [[24 (number)|24]], [[28 (number)|28]], [[30 (number)|30]], [[36 (number)|36]], [[40 (number)|40]], ... {{OEIS|id=A005835}}