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 A376391 #12 Sep 22 2024 11:15:26
%S A376391 1,2,20,386,11252,441722,21867764,1308580226,91904288420,
%T A376391 7413237414602,675503178005108,68631619821747842,7693344955213551428,
%U A376391 943236099444038389082,125565496331888560573172,18037220418654308659836674,2780985275750966018759898212,458079154394191702424821932842
%N A376391 Expansion of e.g.f. ( (1/x) * Series_Reversion( x*(2 - exp(x))^3 ) )^(2/3).
%H A376391 <a href="/index/Res#revert">Index entries for reversions of series</a>
%F A376391 E.g.f.: B(x)^2, where B(x) is the e.g.f. of A367135.
%F A376391 a(n) = (2/(3*n+2)!) * Sum_{k=0..n} (3*n+k+1)! * Stirling2(n,k).
%o A376391 (PARI) my(N=20, x='x+O('x^N)); Vec(serlaplace((serreverse(x*(2-exp(x))^3)/x)^(2/3)))
%o A376391 (PARI) a(n) = 2*sum(k=0, n, (3*n+k+1)!*stirling(n, k, 2))/(3*n+2)!;
%Y A376391 Cf. A367135, A376390.
%K A376391 nonn
%O A376391 0,2
%A A376391 _Seiichi Manyama_, Sep 22 2024