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 A385750 #5 Jul 11 2025 14:52:13
%S A385750 1,1,5,64,1681,78651,5891041,653545390,101785047169,21431911982437,
%T A385750 5927319770834701,2101574777340578156,935265924020629176625,
%U A385750 512945332353359967175999,341342159773993944429746793,272012935493149854994361194426,256689188247205271953044107166721,284051735653584424779666013789038985
%N A385750 a(n) = Sum_{k=0..n} Stirling2(n,k) * (n!/k!)^2.
%F A385750 Sum_{n>=0} a(n) * x^n / n!^2 = Sum_{k>=0} (x^k / k!^2) * Product_{j=1..k} 1 / (1 - j*x).
%F A385750 Sum_{n>=0} a(n) * x^n / n!^3 = Sum_{k>=0} (exp(x) - 1)^k / k!^3.
%t A385750 Table[Sum[StirlingS2[n, k] (n!/k!)^2, {k, 0, n}], {n, 0, 17}]
%t A385750 nmax = 17; CoefficientList[Series[Sum[(Exp[x] - 1)^k/k!^3, {k, 0, nmax}], {x, 0, nmax}], x] Range[0, nmax]!^3
%Y A385750 Cf. A000110, A064618, A119392, A119400, A385751, A385752.
%K A385750 nonn
%O A385750 0,3
%A A385750 _Ilya Gutkovskiy_, Jul 08 2025