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Search: id:A129554
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| A129554 |
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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). |
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+0
2
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| 0, 0, 0, 0, 0, 0, 0, 1, 6, 66, 751, 9737, 131672, 1708295
(list; graph; listen)
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OFFSET
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1,9
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LINKS
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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.
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EXAMPLE
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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.
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CROSSREFS
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Cf. A002562, A129553.
Sequence in context: A119232 A131519 A022024 this_sequence A165229 A127857 A127858
Adjacent sequences: A129551 A129552 A129553 this_sequence A129555 A129556 A129557
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KEYWORD
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more,nonn
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AUTHOR
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R. Douglas Chatham (d.chatham(AT)moreheadstate.edu), Apr 20 2007
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