A271947 a(n) = Product_{k=0..n} (7*k)!.
1, 5040, 439378587648000, 22448266013011335649028997120000000, 6844214664110424043644485692109939233534721371668480000000000000
Offset: 0
Keywords
Links
- Seiichi Manyama, Table of n, a(n) for n = 0..13
- Eric Weisstein's World of Mathematics, Barnes G-Function
- Eric Weisstein's World of Mathematics, Glaisher-Kinkelin Constant
Crossrefs
Programs
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Mathematica
Table[Product[(7*k)!,{k,0,n}],{n,0,8}]
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PARI
{a(n) = prod(k=1, n, (7*k)!)} \\ Seiichi Manyama, Jul 06 2019
Formula
a(n) ~ A^(-1/7) * exp(1/84 - 4*n - 21*n^2/4) * n^(71/84 + 4*n + 7*n^2/2) * 7^(-1/84 + 4*n + 7*n^2/2) * (2*Pi)^(n/2 + 2) / (Gamma(1/7)^(1/7) * Gamma(2/7)^(2/7) * Gamma(3/7)^(3/7) * Gamma(4/7)^(4/7) * Gamma(5/7)^(5/7) * Gamma(6/7)^(6/7)), where A = A074962 is the Glaisher-Kinkelin constant.
Comments