Number of ways to place n nonattacking composite pieces rook + semi-rider[5,5] on an n X n chessboard.
A189847
Number of ways to place n nonattacking composite pieces rook + semi-rider[5,5] on an n X n chessboard.
Terms
- a(0) =1a(1) =2a(2) =6a(3) =24a(4) =120a(5) =696a(6) =4572a(7) =34260a(8) =290328a(9) =2751480a(10) =28426056a(11) =318900264a(12) =3874868280a(13) =50813711808a(14) =716309557440
External references
- oeis: A189847