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 A015769 #15 Feb 18 2021 11:04:49 %S A015769 1,2,3,6,12,14,15,30,35,42,56,70,78,105,140,168,190,210,235,248,264, %T A015769 270,329,357,418,420,470,570,594,616,630,658,695,705,714,744,799,807, %U A015769 812,840,910,940,987,1045,1240,1254,1316,1390,1410,1485,1529 %N A015769 Numbers k such that phi(k) | sigma_11(k). %C A015769 sigma_11(n) = A013959(n) is the sum of the 11th powers of the divisors of n. %H A015769 Amiram Eldar, <a href="/A015769/b015769.txt">Table of n, a(n) for n = 1..10000</a> (terms 1..1000 from Harvey P. Dale) %t A015769 Select[Range[2000],Divisible[DivisorSigma[11,#],EulerPhi[#]]&] (* _Harvey P. Dale_, Feb 07 2015 *) %Y A015769 Cf. A000010, A013959. %Y A015769 Cf. A020492, A015759, A015761, A015762, A015763, A015764, A015765, A015766, A015767, A015768, A015770, A015771, A015773, A015774, A094470. %K A015769 nonn %O A015769 1,2 %A A015769 _Robert G. Wilson v_ %E A015769 Offset corrected by _Amiram Eldar_, Nov 02 2019