a(n) = 4*binomial(4*n+11, n)/(n+4).

Terms

a(0) =1a(1) =12a(2) =114a(3) =1012a(4) =8775a(5) =75516a(6) =649264a(7) =5593068a(8) =48336171a(9) =419276660a(10) =3650774820a(11) =31907617560a(12) =279871768995