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 A356540 #9 Aug 11 2022 08:54:15
%S A356540 1,1,6,40,496,5400,114400,1760080,47671680,1090230400,34312096000,
%T A356540 916877068800,39605683532800,1211405062067200,55580939301888000,
%U A356540 2260295506653184000,115398744818925568000,4928605977341190144000,305987190350116667392000
%N A356540 Expansion of e.g.f. Product_{k>0} 1/(1 - (3 * x)^k)^(1/3^k).
%F A356540 a(0) = 1; a(n) = (n-1)! * Sum_{k=1..n} A356539(k) * a(n-k)/(n-k)!.
%o A356540 (PARI) my(N=20, x='x+O('x^N)); Vec(serlaplace(1/prod(k=1, N, (1-(3*x)^k)^(1/3^k))))
%o A356540 (PARI) a356539(n) = sumdiv(n, d, d*3^(n-d));
%o A356540 a_vector(n) = my(v=vector(n+1)); v[1]=1; for(i=1, n, v[i+1]=(i-1)!*sum(j=1, i, a356539(j)*v[i-j+1]/(i-j)!)); v;
%Y A356540 Cf. A000041, A006950, A356530, A356538.
%Y A356540 Cf. A356539.
%K A356540 nonn
%O A356540 0,3
%A A356540 _Seiichi Manyama_, Aug 11 2022