G.f.: hypergeom([1/24, 5/24, 7/24, 11/24, 13/24, 17/24, 19/24, 23/24], [1/5, 1/4, 2/5, 1/2, 3/5, 3/4, 4/5], 8916100448256/3125*x).
a(n) = binomial(24*n,12*n)*binomial(12*n,4*n)/binomial(5*n,n) = binomial(24*n,12*n)*binomial(13*n,5*n)/binomial(13*n,n). -
Chai Wah Wu, Feb 16 2026
a(n) ~ 2^(24*n-3/2) * 3^(12*n) / (5^(5*n+1/2) * sqrt(Pi*n)). -
Amiram Eldar, Feb 21 2026