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 A381680 #25 Apr 01 2025 12:01:32
%S A381680 1,1,29,263,1565,11217,74412,482638,2987123,18066149,107415185,
%T A381680 623612637,3552605428,19882256022,109518424910,594290145192,
%U A381680 3179607733480,16790129919934,87573088547032,451477766533886,2302069862201553,11616226357007259,58036597014533469
%N A381680 Euler transform of A115224.
%F A381680 G.f.: 1/Product_{k>=1} (1 - x^k)^A115224(k).
%F A381680 G.f.: exp( Sum_{k>=1} sigma_6(k^2)/sigma_3(k^2) * x^k/k ).
%F A381680 a(0) = 1; a(n) = (1/n) * Sum_{k=1..n} sigma_6(k^2)/sigma_3(k^2) * a(n-k).
%F A381680 log(a(n)) ~ 7 * 5^(2/7) * zeta(7)^(1/7) * n^(6/7) / (2^(2/7) * 3^(3/7) * Pi^(4/7)). - _Vaclav Kotesovec_, Mar 04 2025
%t A381680 a[0] = 1; a[n_] := a[n] = Sum[DivisorSigma[6, k^2]/DivisorSigma[3, k^2]*a[n-k], {k, 1, n}]/n; Table[a[n], {n, 0, 30}] (* _Vaclav Kotesovec_, Mar 04 2025 *)
%o A381680 (PARI) my(N=30, x='x+O('x^N)); Vec(exp(sum(k=1, N, sigma(k^2, 6)/sigma(k^2, 3)*x^k/k)))
%Y A381680 Cf. A061255, A381679.
%Y A381680 Cf. A115224, A084220.
%K A381680 nonn
%O A381680 0,3
%A A381680 _Seiichi Manyama_, Mar 04 2025