%I A129552
%S A129552 0,0,0,0,0,0,1,6,37,164,1572,13133,122279,1155103,11347863,112182378
%N A129552 Number of ways to place n+2 queens and 2 pawns on an n X n board so that 
               no two queens attack each other (symmetric solutions count only once).
%H A129552 R. D. Chatham, <a href="http://people.moreheadstate.edu/fs/d.chatham/
               n+kqueens.html">The N+k Queens Problem Page</a>.
%H A129552 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 A129552 a(4)=0 because when 6 queens are placed on a 4 X 4 board, at least two 
               queens will be adjacent and therefore mutually attacking.
%Y A129552 Cf. A002562, A129551.
%Y A129552 Sequence in context: A129651 A097297 A047670 this_sequence A056338 A056328 
               A156185
%Y A129552 Adjacent sequences: A129549 A129550 A129551 this_sequence A129553 A129554 
               A129555
%K A129552 more,nonn
%O A129552 1,8
%A A129552 R. Douglas Chatham (d.chatham(AT)moreheadstate.edu), Apr 20 2007