a(n) = binomial(n+3,n)^3.

Terms

a(0) =1a(1) =64a(2) =1000a(3) =8000a(4) =42875a(5) =175616a(6) =592704a(7) =1728000a(8) =4492125a(9) =10648000a(10) =23393656a(11) =48228544a(12) =94196375a(13) =175616000a(14) =314432000a(15) =543338496a(16) =909853209a(17) =1481544000a(18) =2352637000a(19) =3652264000a(20) =5554637011a(21) =8291469824a(22) =12167000000a(23) =17576000000a(24) =25025203125a(25) =35158608576a(26) =48787170264