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

A276102

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

Terms

    a(0) =1a(1) =50a(2) =8250a(3) =1636250a(4) =349456250a(5) =77636318760

External references