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