a(n) = (n^2+5*n+5)*(2*n+2)!/(n+4)!.

A135487

a(n) = (n^2+5*n+5)*(2*n+2)!/(n+4)!.

Terms

    a(0) =19a(1) =232a(2) =3690a(3) =72600a(4) =1705704a(5) =46650240a(6) =1456902720a(7) =51181804800

External references