50678855040domain: NAppears in sequencesa(n) = binomial(n+5, n)*binomial(n+10, n).at n=15A104673Square array read by ascending antidiagonals: T(n,k) = (2*k)!/k! * ( (2*n*k)! * ((2*n+1)*k)! )/( (n*k)!^2 * ((n+1)*k)!^2 ).at n=33A364506a(n) = (5*n)!*(4*n)! / ((3*n)!^2 * (2*n)! * n!).at n=5A364507