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A221177 Row sums of A141906. 3
1, 2, 9, 1777, 63435145, 623666451641641, 2670266572530016805342641, 7363629673367015952858629874317363281, 18165725639381578540715992641519758891553446152650241, 53130688923813417393347555772148839841537612656804852891837024804533761 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

LINKS

Alois P. Heinz, Table of n, a(n) for n = 0..20

FORMULA

a(n) ~ n^(n^2 - n/2 + 1) / (exp(1/12) * (2*Pi)^((n-1)/2)). - Vaclav Kotesovec, Feb 08 2019

MAPLE

a:= n-> add((n*m)!/m!^n, m=0..n):

seq(a(n), n=0..10);  # Alois P. Heinz, Jan 09 2013

MATHEMATICA

a[n_] := Sum[(n*m)!/m!^n, {m, 0, n}]; Array[a, 10, 0] (* Jean-Fran├žois Alcover, Feb 17 2016 *)

PROG

(PARI) a(n) = sum(m=0, n, (n*m)!/(m!)^n); \\ Michel Marcus, Feb 17 2016

CROSSREFS

Cf. A141906.

Sequence in context: A305851 A208207 A229050 * A181865 A271081 A005167

Adjacent sequences:  A221174 A221175 A221176 * A221178 A221179 A221180

KEYWORD

nonn

AUTHOR

N. J. A. Sloane, Jan 05 2013

STATUS

approved

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Last modified November 28 20:50 EST 2020. Contains 338755 sequences. (Running on oeis4.)