a(n) = (2*n)! * (2*n+1)! / ((n+1)^2 * n!^3).

A204515

a(n) = (2*n)! * (2*n+1)! / ((n+1)^2 * n!^3).

Terms

    a(0) =1a(1) =3a(2) =40a(3) =1050a(4) =42336a(5) =2328480a(6) =163088640a(7) =13913499600

External references