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

Terms

a(0) =1a(1) =45a(2) =225a(3) =637a(4) =1377a(5) =2541a(6) =4225a(7) =6525a(8) =9537a(9) =13357a(10) =18081a(11) =23805a(12) =30625a(13) =38637a(14) =47937a(15) =58621a(16) =70785a(17) =84525a(18) =99937a(19) =117117a(20) =136161a(21) =157165a(22) =180225a(23) =205437a(24) =232897a(25) =262701a(26) =294945a(27) =329725a(28) =367137a(29) =407277