A086687 a(n) = binomial(n!,n).

1, 1, 1, 20, 10626, 190578024, 189492294437160, 16321981448897949868560, 173117930575796585984663510371920, 300649979042426162195454856425990347600496000, 109109335363647915965076917082046041529603540914857910625920

Offset

0,4

Links

Alois P. Heinz, Table of n, a(n) for n = 0..30

Formula

From Vaclav Kotesovec, Jul 02 2016: (Start)

a(n) ~ (n!)^(n-1).

a(n) ~ 2^((n-1)/2) * Pi^((n-1)/2) * n^((2*n+1)*(n-1)/2) / exp(n^2-n-1/12).

(End)

Mathematica

Table[Binomial[n!, n], {n, 0, 12}] (* Vladimir Joseph Stephan Orlovsky, Mar 03 2011*)

Prog

(PARI) for(i=1, 10, print1(", "binomial(i!, i)))

Crossrefs

Cf. A036740.

Main diagonal of A180397.

Sequence in context: A109122 A135420 A045811 * A173790 A028667 A201507

Adjacent sequences: A086684 A086685 A086686 * A086688 A086689 A086690

Keyword

nonn

Author

Jon Perry, Jul 28 2003

Extensions

a(0)=1 prepended by Alois P. Heinz, Nov 06 2016

Status

approved