a(n) is the coefficient of y^(n-1) in Product_{k=0..n-2} (n + (2*n + k)*y + n*y^2), for n >= 1.

A324959

a(n) is the coefficient of y^(n-1) in Product_{k=0..n-2} (n + (2*n + k)*y + n*y^2), for n >= 1.

Terms

    a(0) =1a(1) =4a(2) =60a(3) =1584a(4) =60460a(5) =3029040a(6) =188149822a(7) =13957194496

External references