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 A377529 #14 Feb 04 2025 13:06:41
%S A377529 1,2,10,66,560,5770,69852,970886,15228880,266006610,5119447700,
%T A377529 107617719022,2453167135608,60268223308826,1587381621990556,
%U A377529 44619277892537910,1333135910963656352,42189279001183102882,1409741875877923927332,49597905017847180008126
%N A377529 Expansion of e.g.f. 1/(1 - x * exp(x))^2.
%F A377529 a(n) = n! * Sum_{k=0..n} (k+1) * k^(n-k)/(n-k)!.
%F A377529 a(n) ~ n! * n/((1 + LambertW(1))^2 * LambertW(1)^n). - _Vaclav Kotesovec_, Oct 31 2024
%t A377529 With[{nn=20},CoefficientList[Series[1/(1-x Exp[x])^2,{x,0,nn}],x] Range[0,nn]!] (* _Harvey P. Dale_, Feb 04 2025 *)
%o A377529 (PARI) a(n) = n!*sum(k=0, n, (k+1)*k^(n-k)/(n-k)!);
%Y A377529 Cf. A006153, A377530.
%Y A377529 Cf. A377503, A377527.
%K A377529 nonn,easy
%O A377529 0,2
%A A377529 _Seiichi Manyama_, Oct 30 2024