Number of ways to place 6 nonattacking amazons (superqueens) on a 6 X n board.

Terms

a(0) =0a(1) =0a(2) =0a(3) =0a(4) =0a(5) =0a(6) =0a(7) =0a(8) =16a(9) =170a(10) =920a(11) =3512a(12) =10896a(13) =29020a(14) =68550a(15) =147240a(16) =292996a(17) =547590a(18) =970996a(19) =1646446a(20) =2686212a(21) =4238086a(22) =6492580a(23) =9690846a(24) =14133316a(25) =20189062a(26) =28305876a(27) =39021070a(28) =52972996a(29) =70913286