Number of ways to place 6 nonattacking queens on a 6 X n board.

Terms

a(0) =0a(1) =0a(2) =0a(3) =0a(4) =0a(5) =0a(6) =4a(7) =94a(8) =550a(9) =2292a(10) =7552a(11) =21362a(12) =52856a(13) =117694a(14) =241484a(15) =463038a(16) =838816a(17) =1448002a(18) =2398292a(19) =3832374a(20) =5935120a(21) =8941514a(22) =13145292a(23) =18908302a(24) =26670584a(25) =36961170a(26) =50409604a(27) =67758182a(28) =89874912a(29) =117767194