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

Terms

a(0) =0a(1) =2a(2) =24a(3) =96a(4) =260a(5) =570a(6) =1092a(7) =1904a(8) =3096a(9) =4770a(10) =7040a(11) =10032a(12) =13884a(13) =18746a(14) =24780a(15) =32160a(16) =41072a(17) =51714a(18) =64296a(19) =79040a(20) =96180a(21) =115962a(22) =138644a(23) =164496a(24) =193800a(25) =226850a(26) =263952a(27) =305424a(28) =351596a(29) =402810