Number of ways to place n nonattacking composite pieces rook + rider[4,5] on an n X n chessboard.

A189861

Number of ways to place n nonattacking composite pieces rook + rider[4,5] on an n X n chessboard.

Terms

    a(0) =1a(1) =2a(2) =6a(3) =24a(4) =120a(5) =552a(6) =2826a(7) =17080a(8) =117816a(9) =943250a(10) =7369128a(11) =63533572a(12) =603300392a(13) =6280101222a(14) =71927971040a(15) =836503868762

External references