Number of 2 X 2 matrices having all terms in {1,...,n} and determinant >= 2n.

Terms

a(0) =0a(1) =0a(2) =5a(3) =29a(4) =93a(5) =235a(6) =493a(7) =936a(8) =1622a(9) =2642a(10) =4057a(11) =6055a(12) =8608a(13) =12001a(14) =16297a(15) =21619a(16) =28127a(17) =36170a(18) =45624a(19) =57041a(20) =70350a(21) =85892a(22) =103748a(23) =124748a(24) =148174a(25) =175083a(26) =205683a(27) =239800a(28) =277908a(29) =321224