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%I #12 Jun 23 2019 13:15:18
%S 1,2,3,6,12,14,15,30,35,38,42,54,56,70,78,87,95,105,114,126,135,140,
%T 147,168,174,182,190,209,210,215,216,222,248,258,264,270,285,294,297,
%U 315,357,418,420,430,455,456,540,546,551,570,594,609,616,627
%N Numbers k such that phi(k) | sigma_3(k).
%C sigma_3(k) is the sum of the cubes of the divisors of k (A001158).
%H Amiram Eldar, <a href="/A015761/b015761.txt">Table of n, a(n) for n = 1..10000</a>
%t Select[Range[630], Divisible[DivisorSigma[3, #], EulerPhi[#]] &] (* _Amiram Eldar_, Jun 23 2019 *)
%o (PARI) isok(k) = (sigma(k, 3) % eulerphi(k)) == 0; \\ _Michel Marcus_, Jun 23 2019
%Y Cf. A000010, A001158.
%K nonn
%O 1,2
%A _Robert G. Wilson v_
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