This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A015774 #9 Nov 02 2019 06:42:38 %S A015774 1,2,3,6,12,14,15,30,35,38,42,46,54,56,70,78,87,95,105,114,126,134, %T A015774 135,138,140,147,161,168,174,182,184,190,209,210,215,216,222,230,248, %U A015774 258,264,270,285,294,297,299,315,322,357,398,402,414,418,420 %N A015774 Numbers k such that phi(k) | sigma_15(k). %C A015774 sigma_15(n) is the sum of the 15th powers of the divisors of n. %H A015774 Amiram Eldar, <a href="/A015774/b015774.txt">Table of n, a(n) for n = 1..10000</a> %t A015774 Select[Range[420], Divisible[DivisorSigma[15, #], EulerPhi[#]] &] (* _Amiram Eldar_, Nov 02 2019 *) %Y A015774 Cf. A000010, A013963. %Y A015774 Cf. A020492, A015759, A015761, A015762, A015763, A015764, A015765, A015766, A015767, A015768, A015769, A015770, A015771, A015773, A094470. %K A015774 nonn %O A015774 1,2 %A A015774 _Robert G. Wilson v_ %E A015774 Offset corrected by _Amiram Eldar_, Nov 02 2019