Number of 2 X 2 matrices with all elements in {-n,..,0,..,n} with determinant = 2*permanent.

Terms

a(0) =1a(1) =25a(2) =81a(3) =233a(4) =401a(5) =585a(6) =1009a(7) =1289a(8) =1681a(9) =2377a(10) =2913a(11) =3353a(12) =4497a(13) =5033a(14) =5793a(15) =7097a(16) =8065a(17) =8761a(18) =10721a(19) =11513a(20) =12961a(21) =14873a(22) =16113a(23) =17065a(24) =19873a(25) =21225a(26) =22689a(27) =25465a(28) =27585a(29) =28793