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 A380830 #12 Feb 05 2025 09:23:06
%S A380830 1,4,47,978,29769,1201728,60656679,3681441648,261337079601,
%T A380830 21256149703680,1949700750690879,199146039242552064,
%U A380830 22420399033075845177,2758645779752490872832,368321963942753147683575,53038788218443786432223232,8194316429830951008255159009,1352065789150879084276947222528
%N A380830 Expansion of e.g.f. (1/x) * Series_Reversion( x * exp(-3*x) / (1 + x) ).
%H A380830 <a href="/index/Res#revert">Index entries for reversions of series</a>
%F A380830 E.g.f. A(x) satisfies A(x) = exp(3*x*A(x)) / ( 1 - x*exp(3*x*A(x)) ).
%F A380830 a(n) = n! * Sum_{k=0..n} (3*n+3)^k * binomial(n,k)/(k+1)!.
%F A380830 a(n) = A376094(n+1)/(n+1).
%o A380830 (PARI) a(n) = n!*sum(k=0, n, (3*n+3)^k*binomial(n, k)/(k+1)!);
%Y A380830 Cf. A361182, A380826, A380829.
%Y A380830 Cf. A088690, A380828.
%Y A380830 Cf. A376094.
%K A380830 nonn
%O A380830 0,2
%A A380830 _Seiichi Manyama_, Feb 05 2025