a(n) = 4*n^4 + 24*n^3 + 48*n^2 + 36*n + 8.

Terms

a(0) =8a(1) =120a(2) =528a(3) =1520a(4) =3480a(5) =6888a(6) =12320a(7) =20448a(8) =32040a(9) =47960a(10) =69168a(11) =96720a(12) =131768a(13) =175560a(14) =229440a(15) =294848a(16) =373320a(17) =466488a(18) =576080a(19) =703920a(20) =851928a(21) =1022120a(22) =1216608a(23) =1437600a(24) =1687400a(25) =1968408a(26) =2283120a(27) =2634128a(28) =3024120a(29) =3455880