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 A015764 #21 Jan 20 2019 06:19:18 %S A015764 1,2,3,6,22,33,66,262,750,786,8646,56946,222386,626406,667158,737286, %T A015764 1223123,2446246,2939046,3669369,6804006,7338738,27798250,31684246, %U A015764 41697375,44970486,53817126,62128086,76745867,83394750,95052738,139991987,153491734,174684203 %N A015764 Numbers n such that phi(n) | sigma_6(n). %C A015764 sigma_6(n) is the sum of the 6th powers of the divisors of n. %p A015764 with(numtheory): A015764:=n->`if`(sigma[6](n) mod phi(n) = 0,n,NULL): seq(A015764(n), n=1..10^5); # _Wesley Ivan Hurt_, Mar 10 2015 %t A015764 Select[Range[10^5], Divisible[DivisorSigma[6, #], EulerPhi[#]] &] (* _Amiram Eldar_, Jan 20 2019 *) %Y A015764 Cf. A000010 (phi(n)), A013954 (sigma_6(n)). %Y A015764 Cf. A020492, A015759, A015761, A015762, A015763, A015765, A015766, A015767, A015768, A015769, A015770, A015771, A015773, A015774, A094470. %K A015764 nonn %O A015764 1,2 %A A015764 _Robert G. Wilson v_ %E A015764 More terms from _Labos Elemer_, May 03 2002 %E A015764 a(23)-a(34) from _Amiram Eldar_, Jan 20 2019