A336248 a(n) = (n!)^n * Sum_{k=0..n} (-1)^k / (k!)^n.

1, 0, 1, 26, 20481, 774403124, 2173797080953345, 645067515585218711490294, 27280857986486289638369834192338945, 213095986405176211170558965907644717041658073416, 386654453940903446694477049963665295677203885863801760000000001

Offset: 0

Author

Ilya Gutkovskiy, Jul 14 2020

Keywords

• nonn

Crossrefs

Cf. A000166, A036740, A073701, A336247.

Programs

Mathematica

Table[(n!)^n Sum[(-1)^k/(k!)^n, {k, 0, n}], {n, 0, 10}]

PARI

a(n) = (n!)^n * sum(k=0, n, (-1)^k / (k!)^n); \\ Michel Marcus, Jul 14 2020