Number of 2 X 2 matrices having all terms in {-n,...,0,...,n} and determinant n+1.

Terms

a(0) =0a(1) =4a(2) =24a(3) =116a(4) =128a(5) =408a(6) =296a(7) =788a(8) =748a(9) =1232a(10) =888a(11) =2488a(12) =1312a(13) =2568a(14) =2664a(15) =3860a(16) =2352a(17) =5652a(18) =3032a(19) =6864a(20) =5320a(21) =6456a(22) =4520a(23) =12152a(24) =6356a(25) =9264a(26) =9000a(27) =13288a(28) =7392a(29) =18440