a(n) = (n+1)*n^4.

Terms

a(0) =0a(1) =2a(2) =48a(3) =324a(4) =1280a(5) =3750a(6) =9072a(7) =19208a(8) =36864a(9) =65610a(10) =110000a(11) =175692a(12) =269568a(13) =399854a(14) =576240a(15) =810000a(16) =1114112a(17) =1503378a(18) =1994544a(19) =2606420a(20) =3360000a(21) =4278582a(22) =5387888a(23) =6716184a(24) =8294400a(25) =10156250a(26) =12338352a(27) =14880348a(28) =17825024a(29) =21218430