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 A361557 #11 Mar 15 2023 12:40:43
%S A361557 1,1,4,20,127,977,8789,90267,1040260,13275258,185653535,2821321725,
%T A361557 46265262553,813871304989,15281792484768,304949014412540,
%U A361557 6442741397501699,143633948442619765,3369004776395733829,82919378806522132407,2136425765494805888952
%N A361557 Expansion of e.g.f. exp((exp(x) - 1)/(1-x)).
%F A361557 a(0) = 1; a(n) = Sum_{k=1..n} A002627(k) * binomial(n-1,k-1) * a(n-k).
%o A361557 (PARI) my(N=30, x='x+O('x^N)); Vec(serlaplace(exp((exp(x)-1)/(1-x))))
%Y A361557 Cf. A361532, A361548, A361558.
%Y A361557 Cf. A002627.
%K A361557 nonn
%O A361557 0,3
%A A361557 _Seiichi Manyama_, Mar 15 2023