Number of ways to place n nonattacking composite pieces rook + semi-rider[2,2] on an n X n chessboard.
A189843
Number of ways to place n nonattacking composite pieces rook + semi-rider[2,2] on an n X n chessboard.
Terms
- a(0) =1a(1) =2a(2) =5a(3) =18a(4) =71a(5) =356a(6) =2097a(7) =14212a(8) =105821a(9) =887576a(10) =8093601a(11) =81310936a(12) =876456695a(13) =10257217440a(14) =127631146697
External references
- oeis: A189843