%I A137279
%S A137279 1,4,0,16,40,192,560,3328,11772,63840,259336,1550976,7169656,42410256,
%T A137279 234044160,1366190592
%N A137279 Number of ways of placing (m+1)/2 nonattacking queens on an n X n Mobius 
               chessboard.
%C A137279 The chessboard is an n X n standard chessboard whose left and right edges 
               are twisted connected.
%D A137279 J. Bell and B. Stevens, Results for the n-queens problem on the Mobius 
               board, to appear in the Australasian Journal of Combinatorics, 2008.
%e A137279 a(4)=16 because any queen attacks all but two other squares and every 
               solution is counted twice by enumerating all such placements.
%Y A137279 Cf. A000170, A007705, A002562, A053994, A061989, A061990.
%Y A137279 Sequence in context: A007216 A057378 A002979 this_sequence A167350 A156457 
               A085618
%Y A137279 Adjacent sequences: A137276 A137277 A137278 this_sequence A137280 A137281 
               A137282
%K A137279 nonn
%O A137279 1,2
%A A137279 brett stevens (brett(AT)math.carleton.ca), Mar 13 2008