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A268949
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Number of sequences in {1,...,2n}^(2n) with longest increasing subsequence of length n.
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1
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1, 3, 175, 23611, 5179791, 1583828620, 621893381187, 298289430051783, 169027530016448143, 110485582196129404780, 81829925127960010076736
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OFFSET
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0,2
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LINKS
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FORMULA
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EXAMPLE
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a(1) = 3: 11, 21, 22.
a(2) = 175: 1112, 1113, 1114, 1121, ..., 4414, 4423, 4424, 4434.
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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