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

Terms

a(0) =4a(1) =104a(2) =608a(3) =1940a(4) =4916a(5) =10084a(6) =19052a(7) =32352a(8) =52084a(9) =79308a(10) =116900a(11) =164564a(12) =227860a(13) =306324a(14) =403868a(15) =522256a(16) =667488a(17) =837236a(18) =1041708a(19) =1277060a(20) =1553116a(21) =1871084a(22) =2238452a(23) =2648836a(24) =3121648a(25) =3652200a(26) =4248656a(27) =4911312a(28) =5656784