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

Terms

a(0) =0a(1) =4a(2) =36a(3) =240a(4) =1400a(5) =7560a(6) =38808a(7) =192192a(8) =926640a(9) =4375800a(10) =20323160a(11) =93117024a(12) =421848336a(13) =1892909200a(14) =8424486000a(15) =37228204800a(16) =163493866080a(17) =714083503320