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 A355720 #17 Jul 15 2022 15:05:02
%S A355720 1,1,3,16,113,986,10237,123096,1680737,25668766,433329461,8009178596,
%T A355720 160802065393,3483842906610,80992799730221,2010720004254856,
%U A355720 53081510001375041,1484613248976841958,43846812123456425221,1363477059263944382604
%N A355720 Expansion of e.g.f. exp( x/(2 - exp(x)) ).
%F A355720 a(0) = 1; a(n) = Sum_{k=1..n} A052882(k) * binomial(n-1,k-1) * a(n-k).
%F A355720 a(n) ~ n^(n - 1/4) * exp(sqrt(2*n) - 1/4 - n) / (sqrt(2) * log(2)^n). - _Vaclav Kotesovec_, Jul 15 2022
%o A355720 (PARI) my(N=20, x='x+O('x^N)); Vec(serlaplace(exp(x/(2-exp(x)))))
%o A355720 (PARI) a000670(n) = sum(k=0, n, k!*stirling(n, k, 2));
%o A355720 a_vector(n) = my(v=vector(n+1)); v[1]=1; for(i=1, n, v[i+1]=sum(j=1, i, j*a000670(j-1)*binomial(i-1, j-1)*v[i-j+1])); v;
%Y A355720 Cf. A000248, A355718, A355719.
%Y A355720 Cf. A000670, A052882, A075729.
%K A355720 nonn
%O A355720 0,3
%A A355720 _Seiichi Manyama_, Jul 15 2022