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A193935
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4-nonnesting permutations.
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3
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1, 2, 6, 24, 120, 720, 5034, 40087, 356942, 3500551, 37343168, 428886219, 5257753614, 68306562647, 934747457369, 13404687958473, 200554264435218, 3118638648191005, 50236367074036768, 835860362285064716
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OFFSET
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1,2
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COMMENTS
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Also the number of 4-noncrossing permutations.
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LINKS
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Table of n, a(n) for n=1..20.
Sophie Burrill, Sergi Elizalde, Marni Mishna and Lily Yen, A generating tree approach to k-nonnesting partitions and permutations, arXiv preprint arXiv:1108.5615 [math.CO], 2011-2014.
S. Corteel, Crossings and alignments of permutations, Adv. Appl. Math 38 (2007) 149-163.
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CROSSREFS
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Cf. A193938, A193936, A193937.
Sequence in context: A177547 A324136 A177548 * A177534 A164873 A226438
Adjacent sequences: A193932 A193933 A193934 * A193936 A193937 A193938
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KEYWORD
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nonn,more
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AUTHOR
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Lily Yen, Aug 09 2011
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STATUS
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approved
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