2010/04/22 by Wan-Chen Chuang, Sen‐Peng Eu, Sen-Peng Eu +6
Computer Science · Engineering · Mathematics · #05A05 #05A15 #05A19 #Advanced Combinatorial Mathematics #Combinatorics (math.CO) #FOS: Mathematics #graph theory and CDMA systems #math.CO #msc:05A05 #msc:05A15 #msc:05A19 #semigroups and automata theory
paper · pdf · doi:10.48550/arxiv.1004.3964
18 pages, 9 figures
arxiv created 2010/04/22 · openalex publication_date 2010/04/22 · arxiv updated 2010/04/23 · openalex created_date 2019/06/27 · openalex updated_date 2026/07/28
A permutation σ∈\mathfrakSn is simsun if for all k, the subword of σ restricted to \1,...,k\ does not have three consecutive decreasing elements. The permutation σ is double simsun if both σ and σ-1 are simsun. In this paper we present a new bijection between simsun permutations and increasing 1-2 trees, and show a number of interesting consequences of this bijection in the enumeration of pattern-avoiding simsun and double simsun permutations. We also enumerate the double simsun permutations that avoid each pattern of length three.