Number of ways to place 2 nonattacking kings on an n X n toroidal board.

Terms

a(0) =0a(1) =0a(2) =0a(3) =56a(4) =200a(5) =486a(6) =980a(7) =1760a(8) =2916a(9) =4550a(10) =6776a(11) =9720a(12) =13520a(13) =18326a(14) =24300a(15) =31616a(16) =40460a(17) =51030a(18) =63536a(19) =78200a(20) =95256a(21) =114950a(22) =137540a(23) =163296a(24) =192500a(25) =225446a(26) =262440a(27) =303800a(28) =349856a(29) =400950