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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). 1
0, 0, 0, 0, 0, 0, 1, 6, 37, 164, 1572, 13133, 122279, 1155103, 11347863, 112182378 (list; graph; refs; listen; history; internal format)
OFFSET

1,8

LINKS

R. D. Chatham, The N+k Queens Problem Page.

R. D. Chatham, M. Doyle, G. H. Fricke, J. Reitmann, R. D. Skaggs and M. Wolff, Independence and Domination Separation in Chessboard Graphs, Journal of Combinatorial Mathematics and Combinatorial Computing, to appear.

EXAMPLE

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.

CROSSREFS

Cf. A002562, A129551.

Sequence in context: A129651 A097297 A047670 * A056338 A056328 A156185

Adjacent sequences:  A129549 A129550 A129551 * A129553 A129554 A129555

KEYWORD

more,nonn

AUTHOR

R. Douglas Chatham (d.chatham(AT)moreheadstate.edu), Apr 20 2007

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Last modified February 13 03:38 EST 2012. Contains 205435 sequences.