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 A367139 #13 Nov 07 2023 11:32:28
%S A367139 1,1,9,167,4780,186004,9173780,548563140,38573633016,3119384230176,
%T A367139 285237426927552,29102185296785160,3277703460197645232,
%U A367139 403931173342682581296,54066960915411480743520,7811249803193620134996864,1211525560869437165319590400
%N A367139 E.g.f. satisfies A(x) = 1/(1 + log(1 - x*A(x)^3)).
%F A367139 a(n) = (1/(3*n+1)!) * Sum_{k=0..n} (3*n+k)! * |Stirling1(n,k)|.
%F A367139 a(n) ~ LambertW(3*exp(4))^n * n^(n-1) / (sqrt(3*(1 + LambertW(3*exp(4)))) * exp(n) * (-3 + LambertW(3*exp(4)))^(4*n + 1)). - _Vaclav Kotesovec_, Nov 07 2023
%t A367139 Table[1/(3*n+1)! * Sum[(3*n+k)! * Abs[StirlingS1[n,k]], {k,0,n}], {n,0,20}] (* _Vaclav Kotesovec_, Nov 07 2023 *)
%o A367139 (PARI) a(n) = sum(k=0, n, (3*n+k)!*abs(stirling(n, k, 1)))/(3*n+1)!;
%Y A367139 Cf. A007840, A052802, A367138.
%Y A367139 Cf. A367135, A367137.
%K A367139 nonn
%O A367139 0,3
%A A367139 _Seiichi Manyama_, Nov 06 2023