a(n) = (18*n)!*(4*n)!*(3*n)!/((9*n)!*(8*n)!*(6*n)!*(2*n)!).

A295440

a(n) = (18*n)!*(4*n)!*(3*n)!/((9*n)!*(8*n)!*(6*n)!*(2*n)!).

Terms

    a(0) =1a(1) =43758a(2) =7012604550

External references