A364178 a(n) = (10*n)!*(3*n)!*(n/2)!/((6*n)!*(5*n)!*(3*n/2)!*n!).
1, 168, 83980, 48664320, 29966636700, 19075222663168, 12398706131799988, 8175717823943147520, 5447952226877283703580, 3659442300478634742251520, 2473617870747229982625186480, 1680586987551894402985233481728, 1146602219745194113307246953503300
Offset: 0
Links
- J. W. Bober, Factorial ratios, hypergeometric series, and a family of step functions, arXiv:0709.1977 [math.NT], 2007; J. London Math. Soc., 79, Issue 2, (2009), 422-444.
Crossrefs
Programs
-
Maple
seq( simplify((10*n)!*(3*n)!*(n/2)!/((6*n)!*(5*n)!*(3*n/2)!*n!)), n = 0..15);
Formula
a(n) ~ c^n * 1/sqrt(6*Pi*n), where c = (10/3)^5 * sqrt(3).
a(n) = 1600*(10*n - 1)*(10*n - 3)*(10*n - 7)*(10*n - 9)*(10*n - 11)*(10*n - 13)*(10*n - 17)*(10*n - 19)/(27*n*(n - 1)*(3*n - 2)*(3*n - 4)*(6*n - 1)*(6*n - 5)*(6*n - 7)*(6*n - 11))*a(n-2) with a(0) = 1 and a(1) = 168.
Comments