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a(n) = sigma_n(n^2): sum of n-th powers of divisors of n^2.
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%I #21 Sep 04 2024 18:12:49

%S 1,21,757,69905,9768751,2214363531,678223896393,282578800148737,

%T 150102261281924281,100097761867442455851,81402749387125072783933,

%U 79516409977044969123349715,91733330193268919533506208263

%N a(n) = sigma_n(n^2): sum of n-th powers of divisors of n^2.

%H Harry J. Smith, <a href="/A062755/b062755.txt">Table of n, a(n) for n = 1..100</a>

%t Table[DivisorSigma[n,n^2],{n,20}] (* _Harvey P. Dale_, Sep 04 2024 *)

%o (PARI) a(n)=sigma(n^2, n);

%o (Sage) [sigma(n^2,n)for n in range(1,14)] # _Zerinvary Lajos_, Jun 13 2009

%o (Maxima) makelist(divsum(n^2,n),n,1,100); /* _Emanuele Munarini_, Mar 26 2011 */

%K nonn

%O 1,2

%A _Jason Earls_, Jul 15 2001