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A090051
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Number of chess diagrams that can be obtained in exactly one way in n plies. This is also the number of dual-free proof games in n plies.
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5
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1, 20, 400, 1862, 9373, 51323, 298821, 1965313, 11759158, 66434263, 365037821, 1895313862
(list;
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refs;
listen;
history;
text;
internal format)
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OFFSET
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0,2
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COMMENTS
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Chess diagrams are chess positions without regard to whether castling or en passant capturing is possible. They are counted in A019319. A proof game is a classic type of chess problem.
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LINKS
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CROSSREFS
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KEYWORD
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nonn,hard,more,nice,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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