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A306241
a(n) = Sum_{k=0..n} (k*n)!/n!^k.
2
1, 2, 8, 1702, 63097722, 623372476627154, 2670179107513625597282318, 7363615751879726008424500256018442794, 18165723935734974232438957032838329596079311234990642
OFFSET
0,2
LINKS
FORMULA
a(n) equals (row sums of A120666) + 1.
From Vaclav Kotesovec, Feb 08 2019: (Start)
a(n) ~ A034841(n).
a(n) ~ n^(n^2 - n/2 + 1) / (exp(1/12) * (2*Pi)^((n-1)/2)). (End)
MATHEMATICA
Table[Sum[(k*n)!/n!^k, {k, 0, n}], {n, 0, 10}] (* Vaclav Kotesovec, Feb 08 2019 *)
PROG
(PARI) {a(n) = sum(k=0, n, (k*n)!/n!^k)}
CROSSREFS
KEYWORD
nonn
AUTHOR
Seiichi Manyama, Jan 31 2019
STATUS
approved