A296590 a(n) = Product_{k=0..n} binomial(2*n - k, k).

1, 1, 3, 30, 1050, 132300, 61122600, 104886381600, 674943865596000, 16407885372638760000, 1515727634953623371280000, 534621388490302221024396480000, 722849817707190846398223943885440000, 3759035907022704558524683975387453632000000

Offset

0,3

Comments

Apart from the offset the same as A203469. - R. J. Mathar, Alois P. Heinz, Jan 02 2018

Links

Table of n, a(n) for n=0..13.

Eric Weisstein's World of Mathematics, Barnes G-Function.

Wikipedia, Barnes G-function

Formula

a(n) = A^(3/2) * 2^(n^2 - 1/24) * BarnesG(n + 3/2) / (exp(1/8) * Pi^(n/2 + 1/4) * BarnesG(n + 2)), where A is the Glaisher-Kinkelin constant A074962.

a(n) ~ A^(3/2) * exp(n/2 - 1/8) * 2^(n^2 - 7/24) / (Pi^((n+1)/2) * n^(n/2 + 3/8)), where A is the Glaisher-Kinkelin constant A074962.

Maple

A296590 := proc(n)
    mul( binomial(2*n-k, k), k=0..n) ;
end proc:
seq(A296590(n), n=0..7) ; # R. J. Mathar, Jan 03 2018

Mathematica

Table[Product[Binomial[2*n-k, k], {k, 0, n}], {n, 0, 15}]
Table[Glaisher^(3/2) * 2^(n^2 - 1/24) * BarnesG[n + 3/2] / (E^(1/8) * Pi^(n/2 + 1/4) * BarnesG[n + 2]), {n, 0, 15}]

Crossrefs

Cf. A001142, A007685, A086205, A098694, A110131, A112332, A268196, A296589, A296591.

Sequence in context: A229373 A355400 A203469 * A203478 A012008 A335710

Adjacent sequences: A296587 A296588 A296589 * A296591 A296592 A296593

Keyword

nonn,easy

Author

Vaclav Kotesovec, Dec 16 2017

Status

approved