%I A130712
%S A130712 1,2,2,6,3,21,12,118,56,959,333,9892,3038,154506,38869,3291314,689349,
%T A130712 103050492,17202265,4328976863,615532072,271539093065,30694296121,
%U A130712 22908330863086,2181826599454,2875160955130336,217661432837240
%N A130712 Number of ways of placing non-attacking knights on an n X n chessboard 
               symmetric about the diagonal and under 90 degree rotation.
%Y A130712 Sequence in context: A028421 A081745 A129889 this_sequence A130728 A092384 
               A061915
%Y A130712 Adjacent sequences: A130709 A130710 A130711 this_sequence A130713 A130714 
               A130715
%K A130712 nonn
%O A130712 0,2
%A A130712 Ron Hardin (rhhardin(AT)att.net), Aug 25 2008