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A268504
a(n) = Product_{k=0..n} (3*k)!.
15
1, 6, 4320, 1567641600, 750902834626560000, 981936389699695364014080000000, 6286723722110812136775527266768650240000000000, 321194638135877430211257700556824829511701622266265600000000000000
OFFSET
0,2
COMMENTS
Partial products of A100732. - Michel Marcus, Jul 06 2019
LINKS
FORMULA
a(n) ~ Gamma(1/3)^(1/3) * 3^(3*n^2/2 + 2*n + 11/36) * 2^(n/2 + 1/3) * Pi^(n/2 + 1/3) * n^(3*n^2/2 + 2*n + 19/36) / (A^(1/3) * exp(9*n^2/4 + 2*n - 1/36)), where A = A074962 is the Glaisher-Kinkelin constant.
MATHEMATICA
Table[Product[(3*k)!, {k, 0, n}], {n, 0, 10}]
PROG
(PARI) {a(n) = prod(k=1, n, (3*k)!)} \\ Seiichi Manyama, Jul 06 2019
KEYWORD
nonn
AUTHOR
Vaclav Kotesovec, Apr 16 2016
STATUS
approved