a(n) = binomial(2*n,n)*(n+3)^2/(n+1).

Terms

a(0) =9a(1) =16a(2) =50a(3) =180a(4) =686a(5) =2688a(6) =10692a(7) =42900a(8) =173030a(9) =700128a(10) =2838524a(11) =11522056a(12) =46802700a(13) =190182400a(14) =772913160a(15) =3141129780a(16) =12764118870a(17) =51857916000a(18) =210638666700a(19) =855355383960