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 A316748 #12 Feb 16 2025 08:33:56
%S A316748 1,6,726,365046,481183926,1312473466806,6422019989033526,
%T A316748 51225575261701080246,621880652519326246083126,
%U A316748 10911229213845806303174823606,265743324574322126992546955062326,8697919110119969555113124407898635446,372566878251517048881238923757823056246326
%N A316748 Stirling transform of (3*n)!.
%H A316748 Seiichi Manyama, <a href="/A316748/b316748.txt">Table of n, a(n) for n = 0..149</a>
%H A316748 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/StirlingTransform.html">Stirling Transform</a>.
%F A316748 a(n) ~ (3*n)!.
%F A316748 a(n) ~ sqrt(2*Pi) * 3^(3*n + 1/2) * n^(3*n + 1/2) / exp(3*n).
%F A316748 E.g.f.: Sum_{k>=0} (3*k)! * (exp(x) - 1)^k / k!. - _Seiichi Manyama_, May 21 2022
%t A316748 Table[Sum[StirlingS2[n, k]*(3*k)!, {k, 0, n}], {n, 0, 15}]
%o A316748 (PARI) my(N=20, x='x+O('x^N)); Vec(serlaplace(sum(k=0, N, (3*k)!*(exp(x)-1)^k/k!))) \\ _Seiichi Manyama_, May 21 2022
%Y A316748 Cf. A000670, A064618, A316747, A353774.
%K A316748 nonn
%O A316748 0,2
%A A316748 _Vaclav Kotesovec_, Jul 12 2018