Number of ways to place 7 nonattacking wazirs on a 7 X n board.

Terms

a(0) =0a(1) =2a(2) =1478a(3) =50726a(4) =573797a(5) =3581924a(6) =15516804a(7) =52550366a(8) =149162199a(9) =370817854a(10) =831571604a(11) =1717417198a(12) =3316210152a(13) =6054985120a(14) =10545491888a(15) =17638773534a(16) =28489610297a(17) =44631652698a(18) =68064067456a(19) =101350519742a(20) =147731315314a(21) =211249526076a(22) =296891922604a(23) =410745537182