a(n) = (15*n)!*(4*n)!/((12*n)!*(5*n)!*(2*n)!).

A295455

a(n) = (15*n)!*(4*n)!/((12*n)!*(5*n)!*(2*n)!).

Terms

    a(0) =1a(1) =273a(2) =197925a(3) =163599348a(4) =142968550725

External references