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

Terms

a(0) =0a(1) =1a(2) =12a(3) =108a(4) =800a(5) =5250a(6) =31752a(7) =181104a(8) =988416a(9) =5212350a(10) =26741000a(11) =134132856a(12) =660284352a(13) =3199016548a(14) =15288882000a(15) =72209880000a(16) =337535723520