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 A374874 #4 Sep 13 2024 08:04:30
%S A374874 2,6,45,1260,183600,176490600,1331315425440,90579563457377280,
%T A374874 62660380648301551779840,490943560922866363260804710400,
%U A374874 47971283739623513755756038396090777600,63754384387913077858449560360392597458596659200
%N A374874 Obverse convolution (2^n)**(n!); see Comments.
%C A374874 See A374848 for the definition of obverse convolution and a guide to related sequences.
%t A374874 s[n_] := 2^n; t[n_] := n!;
%t A374874 u[n_] := Product[s[k] + t[n - k], {k, 0, n}]
%t A374874 Table[u[n], {n, 0, 13}]
%Y A374874 Cf. A000079, A000142, A374848.
%K A374874 nonn
%O A374874 0,1
%A A374874 _Clark Kimberling_, Sep 11 2024