A089501 Built from superfactorials A000178.

1, 6, 2880, 870912000, 637129677864960000, 3076276241856388273274880000000, 218470761021769399142244567460557619200000000000, 444747235963340607791337561259087696911923105885061120000000000000000

Offset: 0

Author

Wolfdieter Lang, Nov 07 2003

Keywords

• nonn
• easy

Comments

a(n) appears as a numerator in A089500.

Formula

N(n) := sfac(n-1)*sfac(2*n+1)/sfac(n+1) with sfac(n) := product(k!, k=1..n), n>=1, sfac(0) := 1. sfac(n)= A000178(n).

a(n) ~ 2^(2*n^2 + 5*n + 23/12) * n^(2*n^2 + 2*n -1/12) * Pi^n / (A * exp(3*n^2 + 2*n - 1/12)), where A = A074962 = 1.2824271291... is the Glaisher-Kinkelin constant. - Vaclav Kotesovec, Jul 10 2015