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Number of ways of placing kings with no more than 3 mutual attacks on an n X n chessboard symmetric about both diagonal and antidiagonal.
1

%I #5 Oct 20 2014 18:34:20

%S 1,2,3,7,16,41,121,434,1581,7325,35854,219307,1397579,11370922

%N Number of ways of placing kings with no more than 3 mutual attacks on an n X n chessboard symmetric about both diagonal and antidiagonal.

%K nonn,more,hard

%O 0,2

%A _R. H. Hardin_, Sep 04 2008