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 A094470 #15 Mar 07 2020 06:51:29 %S A094470 1,2,3,6,22,33,66,262,750,786,2182,6546,8646,56946,72006,162066, %T A094470 222386,626406,667158,737286,857526,1223123,1489686,1782726,2446246, %U A094470 2939046,3669369,4388406,4780947,6804006,7338738,9561894,10761126,12157926 %N A094470 Numbers k such that phi(k) | sigma_18(k). %C A094470 A015759 seems to be a true subsequence here. %C A094470 sigma_18(n) is the sum of the 18th powers of the divisors of n (A013966). Conjecture: analogous sequences with any 4j+2 exponent instead of 18, includes all terms of A015759 [with exponent=2]. %H A094470 Amiram Eldar, <a href="/A094470/b094470.txt">Table of n, a(n) for n = 1..130</a> %t A094470 Select[Range[10^6], Divisible[DivisorSigma[18, #], EulerPhi[#]] &] (* _Amiram Eldar_, Mar 07 2020 *) %o A094470 (PARI) isok(k) = (sigma(k, 18) % eulerphi(k)) == 0; \\ _Michel Marcus_, Mar 07 2020 %Y A094470 Cf. A000010, A013966, A015759. %K A094470 nonn %O A094470 1,2 %A A094470 _Labos Elemer_, May 25 2004