Number of 2 X 2 matrices with entries in {0,1,...,n} and even trace with no entries repeated.

Terms

a(0) =0a(1) =0a(2) =0a(3) =8a(4) =48a(5) =144a(6) =360a(7) =720a(8) =1344a(9) =2240a(10) =3600a(11) =5400a(12) =7920a(13) =11088a(14) =15288a(15) =20384a(16) =26880a(17) =34560a(18) =44064a(19) =55080a(20) =68400a(21) =83600a(22) =101640a(23) =121968a(24) =145728a(25) =172224a(26) =202800a(27) =236600a(28) =275184a(29) =317520