login

Reminder: The OEIS is hiring a new managing editor, and the application deadline is January 26.

Obverse convolution (n^2 - n)**(n^2 - n); see Comments.
1

%I #9 Oct 02 2024 14:29:12

%S 0,0,0,144,20736,3686400,846720000,248961081600,91903601147904,

%T 41768738415968256,22963973960761344000,15039892634817600000000,

%U 11578453280457231826944000,10356817418502774061032013824,10655399435864041308654755905536

%N Obverse convolution (n^2 - n)**(n^2 - n); see Comments.

%C See A374848 for the definition of obverse convolution and a guide to related sequences.

%C a(2k+1) is a square for k>=0.

%F a(n) ~ n^(2*n+2) / exp(2*n - Pi*(n-1)/2). - _Vaclav Kotesovec_, Sep 22 2024

%t s[n_] := n^2 - n; t[n_] := n^2 - n;

%t u[n_] := Product[s[k] + t[n - k], {k, 0, n}];

%t Table[u[n], {n, 0, 20}]

%Y Cf. A279019, A374848.

%K nonn

%O 0,4

%A _Clark Kimberling_, Sep 22 2024