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

A211157

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

Terms

    a(0) =4a(1) =164a(2) =528a(3) =1968a(4) =3844a(5) =8836a(6) =14144a(7) =26176a(8) =37540a(9) =61188a(10) =82192a(11) =123120a(12) =157924a(13) =223268a(14) =276608a(15) =374272a(16) =452420a(17) =591524a(18) =700752a(19) =891760a(20) =1038980a(21) =1293700a(22) =1487744a(23) =1818112a(24) =2067172

External references