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Related papers: Shape-Wilf-equivalences for vincular patterns

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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…

Combinatorics · Mathematics 2024-05-24 Alexander Burstein , Tian Han , Sergey Kitaev , Philip Zhang

Vincular or dashed patterns resemble classical patterns except that some of the letters within an occurrence are required to be adjacent. We prove several infinite families of Wilf-equivalences for k-ary words involving vincular patterns…

Combinatorics · Mathematics 2014-03-11 Toufik Mansour , Mark Shattuck

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…

Combinatorics · Mathematics 2014-08-26 Andrew M. Baxter , Mark Shattuck

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…

Combinatorics · Mathematics 2023-06-22 Evan Chen , Shyam Narayanan

We extend the notion of an enumeration scheme developed by Zeilberger and Vatter to the case of vincular patterns (also called "generalized patterns" or "dashed patterns"). In particular we provide an algorithm which takes in as input a set…

Combinatorics · Mathematics 2012-01-17 Andrew M. Baxter , Lara K. Pudwell

We study questions of even-Wilf-equivalence, the analogue of Wilf-equivalence when attention is restricted to pattern avoidance by permutations in the alternating group. Although some Wilf-equivalence results break when considering…

Combinatorics · Mathematics 2011-06-21 Andrew M. Baxter , Aaron D. Jaggard

Partially ordered patterns (POPs) generalize the classical notion of permutation patterns within the framework of pattern avoidance. Building on recent work by Burstein, Han, Kitaev, and Zhang, which introduced the concept of…

Combinatorics · Mathematics 2025-10-22 Sucharita Biswas , Umesh Shankar , Sivaramakrishnan Sivasubramanian

A partially ordered pattern (abbreviated POP) is a partially ordered set (poset) that generalizes the notion of a pattern when we are not concerned with the relative order of some of its letters. The notion of partially ordered patterns…

Combinatorics · Mathematics 2025-07-17 Lintong Wang , Sherry H. F. Yan

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…

Combinatorics · Mathematics 2023-06-22 Murray Tannock , Henning Ulfarsson

We complete the Wilf classification of signed patterns of length 5 for both signed permutations and signed involutions. New general equivalences of patterns are given which prove Jaggard's conjectures concerning involutions in the symmetric…

Combinatorics · Mathematics 2008-01-22 Mark Dukes , Vit Jelínek , Toufik Mansour , Astrid Reifegerste

We prove that the set of patterns {1324,3416725} is Wilf-equivalent to the pattern 1234 and that the set of patterns {2143,3142,246135} is Wilf-equivalent to the set of patterns {2413,3142}. These are the first known unbalanced…

Combinatorics · Mathematics 2014-10-01 Alexander Burstein , Jay Pantone

We give some new Wilf equivalences for signed patterns which allow the complete classification of signed patterns of lengths three and four. The problem is considered for pattern avoidance by general as well as involutive signed…

Combinatorics · Mathematics 2007-05-23 W. M. B. Dukes , T. Mansour , A. Reifegerste

We give a sufficient condition for the two dashed patterns $\tau^{(1)}-\tau^{(2)}-\cdots-\tau^{(\ell)}$ and $\tau^{(\ell)}-\tau^{(\ell-1)}-\cdots-\tau^{(1)}$ to be (strongly) Wilf-equivalent. This permits to solve in a unified way several…

Combinatorics · Mathematics 2012-01-23 Anisse Kasraoui

Inversion sequences are finite sequences of non-negative integers, where the value of each entry is bounded from above by its position. Patterns in inversion sequences have been studied by Corteel-Martinez-Savage-Weselcouch and…

Combinatorics · Mathematics 2020-03-26 Juan S. Auli , Sergi Elizalde

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…

Combinatorics · Mathematics 2014-08-01 Michael Albert , Mathilde Bouvel

In 2020, Bloom and Sagan defined subsets of the symmetric group $\mathfrak{S}_n$ called partial shuffles, and proved a formula for the Schur expansion of the pattern quasisymmetric function associated with a partial shuffle. In their proof,…

Combinatorics · Mathematics 2025-12-25 Michael Albert , Dominic Searles , Matthew Slattery-Holmes

Building off recent work of Garg and Peng, we continue the investigation into classical and consecutive pattern avoidance in rooted forests, resolving some of their conjectures and questions and proving generalizations whenever possible.…

Combinatorics · Mathematics 2023-10-05 Michael Ren

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…

Combinatorics · Mathematics 2021-11-12 Vít Jelínek , Toufik Mansour , José L. Ramírez , Mark Shattuck

Stankova and West proved in 2002 that the patterns 231 and 312 are shape-Wilf-equivalent. Their proof was nonbijective and fairly complicated. We give a new characterization of 231 and 312 avoiding full rook placements and use this to give…

Combinatorics · Mathematics 2012-08-28 Jonathan Bloom , Dan Saracino

The motivation for using qualitative shape descriptions is as follows: qualitative shape descriptions can implicitly act as a schema for measuring the similarity of shapes, which has the potential to be cognitively adequate. Then, shapes…

Computer Vision and Pattern Recognition · Computer Science 2017-05-09 Christopher H. Dorr , Reinhard Moratz
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