Number of ways to place 3 nonattacking amazons (superqueens) on an n X n board.

Terms

a(0) =0a(1) =0a(2) =0a(3) =0a(4) =48a(5) =424a(6) =1976a(7) =6616a(8) =17852a(9) =41544a(10) =86660a(11) =166288a(12) =298616a(13) =508200a(14) =827168a(15) =1296744a(16) =1968676a(17) =2907016a(18) =4189772a(19) =5910944a(20) =8182400a(21) =11136168a(22) =14926536a(23) =19732600a(24) =25760588a(25) =33246664a(26) =42459476a(27) =53703216a(28) =67320392a(29) =83695144