A055705 Numbers n such that n | Sigma_11(n) - Phi(n)^11.

1, 2, 10, 12, 82, 168, 952, 1716, 2732, 2970, 5627, 8185, 11400, 12871, 20104, 20368, 23526, 25749, 70176, 82920, 111194, 117151, 119160, 128790, 134670, 143136, 185140, 193020, 208352, 240408, 247995, 251856, 291368, 354588, 565768, 592006, 642600, 783315

Offset

1,2

Comments

sigma_11(n) is the sum of the 11th powers of the divisors of n (A013959).

Links

Table of n, a(n) for n=1..38.

Mathematica

Do[If[Mod[DivisorSigma[11, n]-EulerPhi[n]^11, n]==0, Print[n]], {n, 10^5}]
Select[Range[800000], Divisible[DivisorSigma[11, #]-EulerPhi[#]^11, #]&] (* Harvey P. Dale, Apr 15 2018 *)

Prog

(PARI) isok(n) = !((sigma(n, 11) - eulerphi(n)^11) % n); \\ Michel Marcus, Mar 02 2014

Crossrefs

Cf. A000010.

Sequence in context: A209445 A181427 A055697 * A156430 A347336 A303356

Adjacent sequences: A055702 A055703 A055704 * A055706 A055707 A055708

Keyword

nonn

Author

Robert G. Wilson v, Jun 09 2000

Extensions

Definition corrected and more terms from Michel Marcus, Mar 02 2014

Status

approved