a(n) = (n^2 - 1)*(n^2 - 3).

Terms

a(0) =3a(1) =0a(2) =3a(3) =48a(4) =195a(5) =528a(6) =1155a(7) =2208a(8) =3843a(9) =6240a(10) =9603a(11) =14160a(12) =20163a(13) =27888a(14) =37635a(15) =49728a(16) =64515a(17) =82368a(18) =103683a(19) =128880a(20) =158403a(21) =192720a(22) =232323a(23) =277728a(24) =329475a(25) =388128a(26) =454275a(27) =528528a(28) =611523a(29) =703920