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A223905
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Number of 4-vexillary permutations in S_n, that is, permutations whose Stanley symmetric function has at most 4 terms or at most 4 Edelman-Greene tableaux.
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4
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1, 1, 2, 6, 24, 120, 717, 4824, 34629, 256689, 1935301
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OFFSET
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0,3
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COMMENTS
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This family is characterized by a finite set of patterns.
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LINKS
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Table of n, a(n) for n=0..10.
S. Billey and B. Pawlowski, Permutation Patterns, Stanley symmetric functions and generalized Specht modules, arXiv:1304.7870 [math.CO], 2013.
Elizabeth Hartung, Hung Phuc Hoang, Torsten Mütze, Aaron Williams, Combinatorial generation via permutation languages. I. Fundamentals, arXiv:1906.06069 [cs.DM], 2019.
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CROSSREFS
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Cf. A005802, A224318.
Sequence in context: A121987 A324132 A177524 * A164872 A226437 A224287
Adjacent sequences: A223902 A223903 A223904 * A223906 A223907 A223908
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KEYWORD
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nonn,more
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AUTHOR
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Sara Billey, Apr 04 2013
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EXTENSIONS
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a(0)=1 prepended by Alois P. Heinz, Jul 31 2019
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STATUS
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approved
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