A055703 - OEIS

%I #10 Mar 02 2014 12:35:51

%S 1,2,12,54,76,90,216,423,514,531,621,2166,2241,2772,2976,4752,5154,

%T 5400,5481,6264,7290,7344,9018,9144,9470,9555,14094,14904,19494,21222,

%U 23780,25848,28323,34830,34911,38220,40122,48768,49079,55782,59400

%N Numbers n such that n | sigma_9(n) - phi(n)^9.

%C sigma_9(n) is the sum of the 9th powers of the divisors of n (A013957).

%t Do[If[Mod[DivisorSigma[9, n]-EulerPhi[n]^9, n]==0, Print[n]], {n, 1, 10^5}]

%o (PARI) isok(n) = !((sigma(n, 9) - eulerphi(n)^9) % n); \\ _Michel Marcus_, Mar 02 2014

%K nonn

%O 1,2

%A _Robert G. Wilson v_, Jun 09 2000

%E Definition corrected by _Michel Marcus_, Mar 02 2014