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 A038065 #24 Apr 12 2025 09:37:20
%S A038065 4,-10,20,-60,204,-690,2340,-8160,29120,-104958,381300,-1397740,
%T A038065 5162220,-19175130,71582716,-268431360,1010580540,-3817763040,
%U A038065 14467258260,-54975528948,209430785460,-799645010850,3059510616420
%N A038065 Product_{k>=1} 1/(1 - x^k)^a(k) = 1 + 4x.
%H A038065 Seiichi Manyama, <a href="/A038065/b038065.txt">Table of n, a(n) for n = 1..1000</a>
%H A038065 N. J. A. Sloane, <a href="/transforms.txt">Euler transform</a>
%F A038065 G.f.: Sum_{k>=1} mu(k)*log(1 + 4*x^k)/k. - _Ilya Gutkovskiy_, May 23 2017
%F A038065 a(n) ~ -(-1)^n * 4^n / n. - _Vaclav Kotesovec_, Jun 12 2018
%F A038065 a(n) = -(1/n) * Sum_{d|n} mu(n/d) * (-4)^d. - _Seiichi Manyama_, Apr 12 2025
%o A038065 (PARI) x='x+O('x^24); Vec(sum(k=1, 24, moebius(k)*log(1 + 4*x^k)/k)) \\ _Indranil Ghosh_, May 24 2017
%Y A038065 Cf. A038063, A038064, A038066, A038067, A038068, A038069, A038070.
%K A038065 sign
%O A038065 1,1
%A A038065 _Christian G. Bower_, Jan 04 1999