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 A306193 #4 Jan 28 2019 10:31:41
%S A306193 2,4,18,392,81250,225061452,9854913828914,7821195286733052688,
%T A306193 128042318400630042200896962,48734103316428964151516768659332500,
%U A306193 480771737247108575104717059364582638896056402,135700420467061659867201490569546772642393389614560348824
%N A306193 a(n) = Product_{k=0..n} (1 + n!/k!).
%F A306193 a(n) = A323717(n) / A000178(n).
%F A306193 a(n) ~ 2 * A * n^(n*(n+1)/2 + 1/12) / exp(n^2/4), where A is the Glaisher-Kinkelin constant A074962.
%t A306193 Table[Product[1 + n!/k!, {k, 0, n}], {n, 0, 12}]
%Y A306193 Cf. A000178, A269700, A323717.
%K A306193 nonn
%O A306193 0,1
%A A306193 _Vaclav Kotesovec_, Jan 28 2019