a(n) = n^4*(n^3 + 1)/2.

Terms

a(0) =0a(1) =1a(2) =72a(3) =1134a(4) =8320a(5) =39375a(6) =140616a(7) =412972a(8) =1050624a(9) =2394765a(10) =5005000a(11) =9750906a(12) =17926272a(13) =31388539a(14) =52725960a(15) =85455000a(16) =134250496a(17) =205211097a(18) =306162504a(19) =447001030a(20) =640080000a(21) =900641511a(22) =1247296072a(23) =1702552644a(24) =2293401600