%I A129554
%S A129554 0,0,0,0,0,0,0,1,6,66,751,9737,131672,1708295
%N A129554 Number of ways to place n+3 queens and 3 pawns on an n X n board so that 
               no two queens attack each other (symmetric solutions count only once).
%H A129554 R. D. Chatham, <a href="http://people.moreheadstate.edu/fs/d.chatham/
               n+kqueens.html">The N+k Queens Problem Page</a>.
%H A129554 R. D. Chatham, M. Doyle, G. H. Fricke, J. Reitmann, R. D. Skaggs and 
               M. Wolff, <a href="http://people.moreheadstate.edu/fs/d.chatham/QueensSep2.pdf">
               Independence and Domination Separation in Chessboard Graphs</a>, 
               Journal of Combinatorial Mathematics and Combinatorial Computing, 
               to appear.
%e A129554 a(4)=0 because when 7 queens are placed on a 4 X 4 board, at least two 
               queens will be adjacent and therefore mutually attacking.
%Y A129554 Cf. A002562, A129553.
%Y A129554 Sequence in context: A119232 A131519 A022024 this_sequence A165229 A127857 
               A127858
%Y A129554 Adjacent sequences: A129551 A129552 A129553 this_sequence A129555 A129556 
               A129557
%K A129554 more,nonn
%O A129554 1,9
%A A129554 R. Douglas Chatham (d.chatham(AT)moreheadstate.edu), Apr 20 2007