%I

%S 1,2,3,15,36,383,1505,28764,197391,6544311,74718810

%N Number of ways of placing kings with no more than 2 mutual attacks on an n X n chessboard symmetric under 180 degree rotation.

%K nonn,more,hard

%O 0,2

%A _R. H. Hardin_, Sep 04 2008