Number of ways to place 9n nonattacking kings on a 18 x 2n chessboard.

A195648

Number of ways to place 9n nonattacking kings on a 18 x 2n chessboard.

Terms

    a(0) =5120a(1) =1501674a(2) =144605184a(3) =7683664202a(4) =282359109140

External references