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A291676 Main diagonal of A291656. 3
0, 1, 10, 3527, 123296356, 757031629267449, 1263498691933197473321646, 823340843273442113630752833831086703, 285062591046216676379736060856308430344065653125000 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

LINKS

Seiichi Manyama, Table of n, a(n) for n = 0..27

FORMULA

a(n) = ((2n-1)!!)^n * Sum_{i=1..n} 1/(2*i-1)^n.

a(n) ~ 2^(n*(2*n + 1)/2) * n^(n^2) / exp(n^2 + 1/24). - Vaclav Kotesovec, Sep 25 2020

MATHEMATICA

Table[((2*n - 1)!!)^n * Sum[1/(2*k - 1)^n, {k, 1, n}], {n, 0, 10}] (* Vaclav Kotesovec, Sep 25 2020 *)

CROSSREFS

Cf. A291656, A335096.

Sequence in context: A115481 A154238 A234144 * A249851 A024139 A320983

Adjacent sequences:  A291673 A291674 A291675 * A291677 A291678 A291679

KEYWORD

nonn

AUTHOR

Seiichi Manyama, Aug 29 2017

STATUS

approved

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Last modified May 27 21:14 EDT 2022. Contains 354110 sequences. (Running on oeis4.)