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 A367164 #11 Nov 10 2023 04:19:25
%S A367164 1,1,5,55,929,21271,616265,21624415,891671009,42263854471,
%T A367164 2264336600825,135325966276975,8926057815521489,644116254555006871,
%U A367164 50477965058305364585,4269330999037434100735,387619447676360230226369,37602089272441407334114471
%N A367164 E.g.f. satisfies A(x) = 1 + A(x)^3 * (1 - exp(-x)).
%F A367164 a(n) = Sum_{k=0..n} (-1)^(n-k) * (3*k)!/(2*k+1)! * Stirling2(n,k).
%F A367164 a(n) ~ sqrt(69) * n^(n-1) / (2^(5/2) * log(27/23)^(n - 1/2) * exp(n)). - _Vaclav Kotesovec_, Nov 10 2023
%t A367164 Table[Sum[(-1)^(n-k) * (3*k)!/(2*k+1)! * StirlingS2[n,k], {k,0,n}], {n,0,20}] (* _Vaclav Kotesovec_, Nov 10 2023 *)
%o A367164 (PARI) a(n) = sum(k=0, n, (-1)^(n-k)*(3*k)!/(2*k+1)!*stirling(n, k, 2));
%Y A367164 Cf. A367155, A367158, A367161.
%Y A367164 Cf. A006531.
%K A367164 nonn
%O A367164 0,3
%A A367164 _Seiichi Manyama_, Nov 07 2023