a(n) = n^5*(n^2 + 1)/2.

Terms

a(0) =0a(1) =1a(2) =80a(3) =1215a(4) =8704a(5) =40625a(6) =143856a(7) =420175a(8) =1064960a(9) =2421009a(10) =5050000a(11) =9824111a(12) =18040320a(13) =31559905a(14) =52975664a(15) =85809375a(16) =134742016a(17) =205879265a(18) =307054800a(19) =448173919a(20) =641600000a(21) =902586321a(22) =1249755760a(23) =1705630895a(24) =2297217024