A337551 Diagonal of A304320.

1, 1, 5, 2317, 153143499, 2331601789103231, 13956629370284243750857868, 50423205212193924706520234988903231406, 154976268837151170420647979803561273009994277188269267, 540838714291102105296873678266047207577891369813629960678503735540658879

Offset: 0

Author

Vaclav Kotesovec, Aug 31 2020

Keywords

• nonn

Links

• Vaclav Kotesovec, Table of n, a(n) for n = 0..26

Crossrefs

Cf. A304320.

Programs

PARI

{T(n, k) = my(A=[1], m); for(i=1, k, A=concat(A, 0); m=#A; A[m] = Vec( exp(x*(m-1)^n +x*O(x^m)) / Ser(A) )[m] ); A[k+1]}
for(n=0, 10, print1(T(n, n), ", ")) \\ after Paul D. Hanna

Formula

a(n) ~ n^(n^2) / n!.

a(n) ~ exp(n) * n^(n^2 - n - 1/2) / sqrt(2*Pi).