Number of 2 X 2 matrices having all elements in {-n,...n} and determinant 4.

Terms

a(0) =0a(1) =0a(2) =52a(3) =116a(4) =364a(5) =492a(6) =684a(7) =876a(8) =1260a(9) =1452a(10) =1836a(11) =2156a(12) =2668a(13) =3052a(14) =3628a(15) =3884a(16) =4652a(17) =5164a(18) =5740a(19) =6316a(20) =7340a(21) =7724a(22) =8684a(23) =9388a(24) =10156a(25) =10796a(26) =11948a(27) =12524a(28) =14060a(29) =14956