Number of singular 2 X 2 matrices having all elements in {-n,...,n}.

Terms

a(0) =1a(1) =33a(2) =129a(3) =289a(4) =545a(5) =833a(6) =1313a(7) =1729a(8) =2369a(9) =3041a(10) =3905a(11) =4577a(12) =5857a(13) =6657a(14) =7905a(15) =9345a(16) =10881a(17) =11937a(18) =13953a(19) =15137a(20) =17441a(21) =19521a(22) =21537a(23) =22977a(24) =26177a(25) =28257a(26) =30657a(27) =33249a(28) =36577a(29) =38401