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相关论文: Equidistribution of mesh patterns of short length

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A systematic study of avoidance of mesh patterns of length 2 was conducted by Hilmarsson et al., where 25 out of 65 non-equivalent cases were solved. In this paper, we give 27 distribution results for these patterns including 14…

组合数学 · 数学 2019-06-03 Sergey Kitaev , Philip B. Zhang

This paper starts the Wilf-classification of mesh patterns of length 2. Although there are initially 1024 patterns to consider we introduce automatic methods to reduce the number of potentially different Wilf-classes to at most 65. By…

A systematic study of avoidance of mesh patterns of length 2 was conducted by Hilmarsson et al. in 2015. In a recent paper Kitaev and Zhang examined the distribution of the aforementioned patterns. The aim of this paper is to prove more…

组合数学 · 数学 2020-07-28 Bin Han , Jiang Zeng

Two mesh patterns are coincident if they are avoided by the same set of permutations, and are Wilf-equivalent if they have the same number of avoiders of each length. We provide sufficient conditions for coincidence of mesh patterns, when…

组合数学 · 数学 2023-06-22 Murray Tannock , Henning Ulfarsson

Br\"and\'en and Claesson introduced mesh patterns to provide explicit expansions for certain permutation statistics as linear combinations of (classical) permutation patterns. The first systematic study of avoidance of mesh patterns was…

组合数学 · 数学 2019-03-05 Sergey Kitaev , Philip B. Zhang , Xutong Zhang

A notable problem within permutation patterns that has attracted considerable attention in literature since 1973 is the search for a bijective proof demonstrating that 123-avoiding and 132-avoiding permutations are equinumerous, both…

组合数学 · 数学 2024-08-20 Sergey Kitaev , Shuzhen Lv

We present two families of Wilf-equivalences for consecutive and quasi-consecutive vincular patterns. These give new proofs of the classification of consecutive patterns of length $4$ and $5$. We then prove additional equivalences to…

组合数学 · 数学 2023-06-22 Evan Chen , Shyam Narayanan

Motivated by a correlation between the distribution of descents over permutations that avoid a consecutive pattern and those avoiding the respective quasi-consecutive pattern, as established in this paper, we obtain a complete $\des$-Wilf…

组合数学 · 数学 2025-02-17 Yan Wang , Qi Fang , Shishuo Fu , Sergey Kitaev , Haijun Li

We classify all bi-vincular patterns of length two and three according to the number of permutations avoiding them. These patterns were recently defined by Bousquet-Melou et. al., and are natural generalizations of Babson and…

组合数学 · 数学 2009-11-17 Robert Parviainen

The study of joint equidistributions of mesh patterns 123 and 132 with the same symmetric shadings was recently initiated by Kitaev and Lv, where 75 of 80 potential joint equidistributions were proven. In this paper, we prove 112 out of 126…

组合数学 · 数学 2025-12-09 Shuzhen Lv , Philip B. Zhang

Jel\'inek, Mansour, and Shattuck studied Wilf-equivalence among pairs of patterns of the form $\{\sigma,\tau\}$ where $\sigma$ is a set partition of size $3$ with at least two blocks. They obtained an upper bound for the number of…

组合数学 · 数学 2021-08-09 Krishna Menon , Anurag Singh

We develop a new, powerful method for counting elements in a multiset. As a first application, we use this algorithm to study the number of occurrences of patterns in a permutation. For patterns of length 3 there are two Wilf classes, and…

组合数学 · 数学 2024-03-05 Andrew R Conway , Anthony J Guttmann

In this paper, we study the Wilf-type equivalence relations among multiset permutations. We identify all multiset equivalences among pairs of patterns consisting of a pattern of length three and another pattern of length at most four. To…

组合数学 · 数学 2021-11-12 Vít Jelínek , Toufik Mansour , José L. Ramírez , Mark Shattuck

Three complementation-like involutions are constructed on permutations to prove, and in some cases generalize, all remaining fourteen joint symmetric equidistribution conjectures of Lv and Zhang. Further enumerative results are obtained for…

组合数学 · 数学 2025-07-08 Qi Fang , Shishuo Fu , Sergey Kitaev , Haijun Li

In this paper, we extend recent results by Lv and Kitaev by proving 20 (out of 22 possible) joint equidistributions of mesh patterns 123 and 321 with symmetric shadings, as well as all 36 joint equidistributions of these patterns with…

组合数学 · 数学 2026-02-26 Shuzhen Lv , Philip B. Zhang

We prove a conjecture of Gao and Kitaev on Wilf-equivalence of sets of patterns {12345,12354} and {45123,45213} that extends the list of 10 related conjectures proved in the literature in a series of papers. To achieve our goals, we prove…

组合数学 · 数学 2024-05-24 Alexander Burstein , Tian Han , Sergey Kitaev , Philip Zhang

We prove several Wilf-equivalences for vincular patterns of length 4, some of which generalize to infinite families of vincular patterns. We also present functional equations for the generating functions for the number of permutations of…

组合数学 · 数学 2014-08-26 Andrew M. Baxter , Mark Shattuck

An open conjecture in pattern avoidance theory is that the distribution of the major index among 321-avoiding permutations is distributed unimodally. We construct a formula for this distribution, and in the case of 2 descents prove…

组合数学 · 数学 2017-07-14 William J. Keith

The existence of apparently coincidental equalities (also called Wilf-equivalences) between the enumeration sequences, or generating functions, of various hereditary classes of combinatorial structures has attracted significant interest. We…

组合数学 · 数学 2014-08-01 Michael Albert , Mathilde Bouvel

Inspired by the results of Baik, Deift and Johansson on the limiting distribution of the lengths of the longest increasing subsequences in random permutations, we find those limiting distributions for pattern-restricted permutations in…

组合数学 · 数学 2009-09-29 Emeric Deutsch , A. J. Hildebrand , Herbert S. Wilf
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