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 A094468 #23 Jan 13 2025 04:08:19 %S A094468 1,2,3,6,14,42,3810,26670,34162,41256,48546,87096,102486,131934, %T A094468 210482,288792,315723,318990,430122,529848,609672,631446,979830, %U A094468 1023366,1203960,1473374,1683126,1920699,2210061,2241934,2506086,2549610 %N A094468 Numbers k such that sum of 9th powers of divisors of k is divisible by the square of Euler-phi of k. %H A094468 Amiram Eldar, <a href="/A094468/b094468.txt">Table of n, a(n) for n = 1..420</a> %F A094468 A013957(k)/A000010(k)^2 is an integer. %t A094468 Select[Range[2600000],Divisible[Total[Divisors[#]^9],(EulerPhi[#])^2]&] (* _Harvey P. Dale_, Mar 04 2011 *) %o A094468 (PARI) for(n=1,10000000,if(Mod(sigma(n,9),eulerphi(n)^2)==0,print1(n,","))) \\ C. Ronaldo %Y A094468 Cf. A015763, A000010, A091285, A013957. %K A094468 nonn %O A094468 1,2 %A A094468 _Labos Elemer_, May 19 2004 %E A094468 More terms from C. Ronaldo (aga_new_ac(AT)hotmail.com), Jan 18 2005