Number of nonequivalent solutions to the order n checkerboard problem up to reflection and rotation: place n pieces on an n X n board so there is exactly one piece in each row, column and main diagonal.

A064280

Number of nonequivalent solutions to the order n checkerboard problem up to reflection and rotation: place n pieces on an n X n board so there is exactly one piece in each row, column and main diagonal.

Terms

    a(0) =1a(1) =0a(2) =0a(3) =1a(4) =4a(5) =12a(6) =86a(7) =696a(8) =6150a(9) =61760a(10) =673256a(11) =8137200a(12) =105074420a(13) =1479237312a(14) =22077680616a(15) =354753059584

External references