Number of 2 X 2 matrices with all terms in {0,1,...,n} and even determinant.

Terms

a(0) =1a(1) =10a(2) =65a(3) =160a(4) =457a(5) =810a(6) =1681a(7) =2560a(8) =4481a(9) =6250a(10) =9841a(11) =12960a(12) =18985a(13) =24010a(14) =33377a(15) =40960a(16) =54721a(17) =65610a(18) =84961a(19) =100000a(20) =126281a(21) =146410a(22) =181105a(23) =207360a(24) =252097a(25) =285610a(26) =342161a(27) =384160a(28) =454441a(29) =506250