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A248900
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Number of permutations of [n] avoiding patterns 2431 and 54321.
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1
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1, 1, 2, 6, 23, 102, 492, 2492, 13003, 69172, 372963, 2031174, 11148948, 61588814, 342068774, 1908740089, 10694374242, 60137305751, 339276548456, 1919787554118, 10892575241125, 61957028188350, 353224194632459, 2018076850631391, 11552829351121139, 66259093178740462
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OFFSET
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0,3
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LINKS
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EXAMPLE
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a(4) = 23 because all permutations of length 4 except 2431 lie in this set.
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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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