A375056 Obverse convolution (n^2 - n)**(n^2 - n); see Comments.

0, 0, 0, 144, 20736, 3686400, 846720000, 248961081600, 91903601147904, 41768738415968256, 22963973960761344000, 15039892634817600000000, 11578453280457231826944000, 10356817418502774061032013824, 10655399435864041308654755905536

Offset: 0

Author

Clark Kimberling, Sep 22 2024

Keywords

• nonn

Comments

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

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

Crossrefs

Cf. A279019, A374848.

Programs

Mathematica

s[n_] := n^2 - n; t[n_] := n^2 - n;
u[n_] := Product[s[k] + t[n - k], {k, 0, n}];
Table[u[n], {n, 0, 20}]

Formula

a(n) ~ n^(2*n+2) / exp(2*n - Pi*(n-1)/2). - Vaclav Kotesovec, Sep 22 2024