a(n) = binomial(2*n,n) * (2*n+1)^2.

Terms

a(0) =1a(1) =18a(2) =150a(3) =980a(4) =5670a(5) =30492a(6) =156156a(7) =772200a(8) =3719430a(9) =17551820a(10) =81477396a(11) =373173528a(12) =1690097500a(13) =7582037400a(14) =33738060600a(15) =149067936720a(16) =654576544710