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 A355180 #18 Feb 16 2025 08:34:03
%S A355180 0,0,0,0,4,10,20,35,6776,60564,352920,1663365,126625180,2361079006,
%T A355180 27334747804,245495250455,11174333090480,328952158255400,
%U A355180 6245314009946736,90576650639967369,3209305759254634740,122557203047084965810,3365068665450300234580
%N A355180 Expansion of e.g.f. -LambertW(x^3 * (1 - exp(x)))/6.
%H A355180 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/LambertW-Function.html">Lambert W-Function</a>.
%F A355180 a(n) = (n!/6) * Sum_{k=1..floor(n/4)} k^(k-1) * Stirling2(n-3*k,k)/(n-3*k)!.
%o A355180 (PARI) my(N=20, x='x+O('x^N)); concat([0, 0, 0, 0], Vec(serlaplace(-lambertw(x^3*(1-exp(x)))/6)))
%o A355180 (PARI) a(n) = n!*sum(k=1, n\4, k^(k-1)*stirling(n-3*k, k, 2)/(n-3*k)!)/6;
%Y A355180 Cf. A048802, A355179, A357267.
%K A355180 nonn
%O A355180 0,5
%A A355180 _Seiichi Manyama_, Sep 24 2022