a(n) = (6*n)!*(5*n)!*(2*n)! / ((4*n)!^2 * (3*n)! * n!^2).

A364511

a(n) = (6*n)!*(5*n)!*(2*n)! / ((4*n)!^2 * (3*n)! * n!^2).

Terms

    a(0) =1a(1) =50a(2) =8910a(3) =2011100a(4) =503909070a(5) =133954543800

External references