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A143880
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Number of ways of placing kings with no more than 2 mutual attacks on an n X n chessboard symmetric under 180 degree rotation.
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1
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1, 2, 3, 15, 36, 383, 1505, 28764, 197391, 6544311, 74718810
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OFFSET
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0,2
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LINKS
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CROSSREFS
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KEYWORD
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nonn,more,hard
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AUTHOR
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STATUS
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approved
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