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 A376390 #13 Sep 22 2024 11:15:21
%S A376390 1,3,33,666,19923,795438,39849549,2405748978,170114699247,
%T A376390 13796351753670,1262691211748865,128760309960844554,
%U A376390 14478116911623185163,1779761344294187865198,237465809999666515842261,34179385495053448088261154,5279029838285444642785757415,870905593631158913782753290198
%N A376390 Expansion of e.g.f. (1/x) * Series_Reversion( x*(2 - exp(x))^3 ).
%H A376390 <a href="/index/Res#revert">Index entries for reversions of series</a>
%F A376390 E.g.f. A(x) satisfies A(x) = 1/(2 - exp(x*A(x)))^3.
%F A376390 E.g.f.: B(x)^3, where B(x) is the e.g.f. of A367135.
%F A376390 a(n) = (3/(3*n+3)!) * Sum_{k=0..n} (3*n+k+2)! * Stirling2(n,k).
%o A376390 (PARI) my(N=20, x='x+O('x^N)); Vec(serlaplace(serreverse(x*(2-exp(x))^3)/x))
%o A376390 (PARI) a(n) = 3*sum(k=0, n, (3*n+k+2)!*stirling(n, k, 2))/(3*n+3)!;
%Y A376390 Cf. A367135, A376391.
%Y A376390 Cf. A226515.
%K A376390 nonn
%O A376390 0,2
%A A376390 _Seiichi Manyama_, Sep 22 2024