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 A367155 #12 Nov 10 2023 04:00:39 %S A367155 1,1,5,56,948,21804,634284,22348584,925322784,44039346264, %T A367155 2369167375656,142173632632272,9416315321258928,682290228636729504, %U A367155 53689645309437175968,4559660591348115191808,415683140400707316145920,40490500091575002629253120 %N A367155 E.g.f. satisfies A(x) = 1 + A(x)^3 * log(1 + x). %F A367155 a(n) = Sum_{k=0..n} (3*k)!/(2*k+1)! * Stirling1(n,k). %F A367155 a(n) ~ 9 * n^(n-1) / (2^(5/2) * (exp(4/27) - 1)^(n - 1/2) * exp(n + 2/27)). - _Vaclav Kotesovec_, Nov 10 2023 %t A367155 Table[Sum[(3*k)!/(2*k+1)! * StirlingS1[n,k], {k,0,n}], {n,0,20}] (* _Vaclav Kotesovec_, Nov 10 2023 *) %o A367155 (PARI) a(n) = sum(k=0, n, (3*k)!/(2*k+1)!*stirling(n, k, 1)); %Y A367155 Cf. A367158, A367161, A367164. %Y A367155 Cf. A087152. %K A367155 nonn %O A367155 0,3 %A A367155 _Seiichi Manyama_, Nov 07 2023