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 A370240 #13 Feb 13 2024 03:43:26
%S A370240 1,1,1,1,1,1,1,9,1,1,1,1,1,1,1,9,1,1,1,1,1,1,1,9,1,1,28,1,1,1,1,9,1,1,
%T A370240 1,1,1,1,1,9,1,1,1,1,1,1,1,9,1,1,1,1,1,28,1,9,1,1,1,1,1,1,1,9,1,1,1,1,
%U A370240 1,1,1,9,1,1,1,1,1,1,1,9,28,1,1,1,1,1
%N A370240 The sum of divisors of n that are cubes of squarefree numbers.
%C A370240 First differs from A366904 at n = 32, and from A113061 at n = 64.
%H A370240 Amiram Eldar, <a href="/A370240/b370240.txt">Table of n, a(n) for n = 1..10000</a>
%F A370240 Multiplicative with a(p^e) = 1 for e <= 2, and a(p^e) = 1 + p^3 for e >= 3.
%F A370240 Dirichlet g.f.: zeta(s)*zeta(3*s-3)/zeta(6*s-6).
%F A370240 Sum_{k=1..n} a(k) ~ c * n^(4/3) + n, where c = 3*zeta(4/3)/(2*Pi^2) = 0.5472769126... .
%t A370240 f[p_, e_] := If[e <= 2, 1, 1 + p^3]; a[1] = 1; a[n_] := Times @@ f @@@ FactorInteger[n]; Array[a, 100]
%o A370240 (PARI) a(n) = {my(f = factor(n)); prod(i = 1, #f~, if(f[i,2] <= 2, 1, 1 + f[i,1]^3));}
%Y A370240 Cf. A062838, A113061, A366904, A370239.
%K A370240 nonn,easy,mult
%O A370240 1,8
%A A370240 _Amiram Eldar_, Feb 13 2024