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

Terms

a(0) =0a(1) =0a(2) =6a(3) =40a(4) =125a(5) =323a(6) =647a(7) =1235a(8) =2074a(9) =3337a(10) =5057a(11) =7477a(12) =10436a(13) =14490a(14) =19436a(15) =25591a(16) =33015a(17) =42259a(18) =52849a(19) =65833a(20) =80528a(21) =97909a(22) =117905a(23) =141163a(24) =166651a(25) =196474a(26) =229796a(27) =267289a(28) =308712a(29) =355766