Number of ways to place n nonattacking composite pieces queen + rider[3,4] on an n X n chessboard.
A189879
Number of ways to place n nonattacking composite pieces queen + rider[3,4] on an n X n chessboard.
Terms
- a(0) =1a(1) =0a(2) =0a(3) =2a(4) =2a(5) =4a(6) =28a(7) =0a(8) =20a(9) =20a(10) =180a(11) =520a(12) =1888a(13) =6016a(14) =22480a(15) =105236a(16) =433500a(17) =1933604a(18) =9687268a(19) =50998366a(20) =269523272a(21) =1507984008
External references
- oeis: A189879