a(n) = (20*n)!*(6*n)!*n!/((12*n)!*(10*n)!*(3*n)!*(2*n)!).

A295470

a(n) = (20*n)!*(6*n)!*n!/((12*n)!*(10*n)!*(3*n)!*(2*n)!).

Terms

    a(0) =1a(1) =83980a(2) =29966636700

External references