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 A353664 #17 May 08 2022 08:23:49
%S A353664 1,0,0,6,36,150,900,9366,101556,1031190,10995300,134640726,1844184276,
%T A353664 26656678230,400614423300,6347263038486,106960986110196,
%U A353664 1905688502565270,35546025523227300,691014283378745046,13999772792477879316,295570215436360196310
%N A353664 Expansion of e.g.f. exp((exp(x) - 1)^3).
%F A353664 G.f.: Sum_{k>=0} (3*k)! * x^(3*k)/(k! * Product_{j=1..3*k} (1 - j * x)).
%F A353664 a(0) = 1; a(n) = 6 * Sum_{k=1..n} binomial(n-1,k-1) * Stirling2(k,3) * a(n-k).
%F A353664 a(n) = Sum_{k=0..floor(n/3)} (3*k)! * Stirling2(n,3*k)/k!.
%o A353664 (PARI) my(N=30, x='x+O('x^N)); Vec(serlaplace(exp((exp(x)-1)^3)))
%o A353664 (PARI) my(N=30, x='x+O('x^N)); Vec(sum(k=0, N, (3*k)!*x^(3*k)/(k!*prod(j=1, 3*k, 1-j*x))))
%o A353664 (PARI) a_vector(n) = my(v=vector(n+1)); v[1]=1; for(i=1, n, v[i+1]=6*sum(j=1, i, binomial(i-1, j-1)*stirling(j, 3, 2)*v[i-j+1])); v;
%o A353664 (PARI) a(n) = sum(k=0, n\3, (3*k)!*stirling(n, 3*k, 2)/k!);
%Y A353664 Cf. A000110, A052859, A353665.
%Y A353664 Cf. A327504, A353344, A353774.
%K A353664 nonn
%O A353664 0,4
%A A353664 _Seiichi Manyama_, May 07 2022