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%I #7 Sep 15 2024 10:55:43
%S 0,1,12,216,5600,198000,9144576,533653120,38339288064,3320915760000,
%T 340950896000000,40905397939101696,5666507699182387200,
%U 897094997540641908736,160875919414586880000000,32426573960663769600000000,7296186062362650316241371136
%N Obverse convolution (n)**(n(n+1)/2); see Comments.
%C See A374848 for the definition of obverse convolution and a guide to related sequences.
%F a(n) ~ n^(2*n+1) / (2^n * exp(2*n + 2 - Pi*sqrt(2*n))). - _Vaclav Kotesovec_, Sep 15 2024
%t s[n_] := n; t[n_] := n (n + 1)/2;
%t u[n_] := Product[s[k] + t[n - k], {k, 0, n}]
%t Table[u[n], {n, 0, 20}]
%Y Cf. A000027, A000217, A374848.
%K nonn
%O 0,3
%A _Clark Kimberling_, Sep 14 2024