A133051 Squares of perfect numbers.

36, 784, 246016, 66064384, 1125625045712896, 73785850399226331136, 18889393873953262403584, 5316911978187903335626628646131728384, 7067388259113537312203207839508118631205775474686154970915275376716414976

Offset

1,1

Links

Table of n, a(n) for n=1..9.

Formula

a(n) = A000396(n)^2

Example

a(2)=784 because the second perfect number is 28 and 28^2=784.

Mathematica

Select[Range[9000], DivisorSigma[1, #]== 2*# &]^2 (* G. C. Greubel, Oct 03 2017 *)

Crossrefs

Cf. A000290, A001248. Perfect numbers: A000396.

Sequence in context: A228331 A014772 A110206 * A215605 A173187 A028222

Adjacent sequences: A133048 A133049 A133050 * A133052 A133053 A133054

Keyword

nonn

Author

Omar E. Pol, Oct 30 2007

Extensions

More terms from Olaf Voß, Feb 13 2008

Status

approved