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A126685
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In chess, the number of checkmate dual-free proof games in n plies.
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0
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0, 0, 0, 0, 0, 3, 51, 1106, 3813, 47300, 216420, 2057581, 10276981, 74358924
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OFFSET
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0,6
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COMMENTS
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Among all the proof game problems counted in A090051, this is the number of problems ending in checkmate.
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LINKS
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EXAMPLE
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a(5)=3 because there are three checkmate proof games in 5 plies:
1. e4 e5 2. Qh5 Ke7 3. Qxe5#
1. e3 e5 2. Qh5 Ke7 3. Qxe5#
1. e4 f5 2. exf5 g5 3. Qh5#
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CROSSREFS
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KEYWORD
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hard,nonn,fini
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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