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

Terms

a(0) =0a(1) =5a(2) =24a(3) =93a(4) =272a(5) =645a(6) =1320a(7) =2429a(8) =4128a(9) =6597a(10) =10040a(11) =14685a(12) =20784a(13) =28613a(14) =38472a(15) =50685a(16) =65600a(17) =83589a(18) =105048a(19) =130397a(20) =160080a(21) =194565a(22) =234344a(23) =279933a(24) =331872a(25) =390725a(26) =457080a(27) =531549a(28) =614768a(29) =707397