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 A380047 #8 Jan 11 2025 10:26:35
%S A380047 1,3,12,45,132,135,-702,6573,111576,-634581,-19482690,104641713,
%T A380047 5438689380,-21226768017,-2173847986086,3249084663765,
%U A380047 1168505502268848,2167390942251219,-807540016560944778,-5035872168333504807,693302551375611396540,8209523136574257223383
%N A380047 E.g.f. A(x) satisfies A(x) = 1 + 3*x*exp(x)*A(x)^(1/3).
%F A380047 E.g.f.: B(x)^3, where B(x) is the e.g.f. of A380051.
%F A380047 a(n) = n! * Sum_{k=0..n} 3^k * k^(n-k) * binomial(k/3+1,k)/( (k/3+1)*(n-k)! ).
%o A380047 (PARI) a(n) = n!*sum(k=0, n, 3^k*k^(n-k)*binomial(k/3+1, k)/((k/3+1)*(n-k)!));
%Y A380047 Cf. A006153, A380046.
%Y A380047 Cf. A380051.
%K A380047 sign
%O A380047 0,2
%A A380047 _Seiichi Manyama_, Jan 11 2025