Results 21 to 30 of about 176,018 (136)

Descents and des-Wilf equivalence of permutations avoiding certain nonclassical patterns [PDF]

open access: yesInvolve, 2019
A frequent topic in the study of pattern avoidance is identifying when two sets of patterns $Π, Π'$ are Wilf equivalent, that is, when $|\text{Av}_n(Π)| = |\text{Av}_n(Π')|$ for all $n$. In recent work of Dokos et al. the notion of Wilf equivalence was refined to reflect when avoidance of classical patterns preserves certain statistics. In this article,
Robert Davis
exaly   +4 more sources

Constraining strong c-Wilf equivalence using cluster poset asymptotics

open access: yesAdvances in Applied Mathematics, 2019
Let $π\in \mathfrak{S}_m$ and $σ\in \mathfrak{S}_n$ be permutations. An occurrence of $π$ in $σ$ as a consecutive pattern is a subsequence $σ_i σ_{i+1} \cdots σ_{i+m-1}$ of $σ$ with the same order relations as $π$. We say that patterns $π, τ\in \mathfrak{S}_m$ are strongly c-Wilf equivalent if for all $n$ and $k$, the number of permutations in ...
Mitchell Lee, Ashwin Sah
exaly   +6 more sources

A refinement of Wilf-equivalence for patterns of length 4

open access: yesJournal of Combinatorial Theory - Series A, 2014
In their paper \cite{DokosDwyer:Permutat12}, Dokos et al. conjecture that the major index statistic is equidistributed among 1423-avoiding, 2413-avoiding, and 2314-avoiding permutations. In this paper we confirm this conjecture by constructing two major index preserving bijections, $Θ:S_n(1423)\to S_n(2413)$ and $Ω:S_n(2314)\to S_n(2413)$.
exaly   +5 more sources

Proof of a conjecture on the shape-Wilf-equivalence for partially ordered patterns

open access: yesEuropean Journal of Combinatorics
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 provides a convenient language to deal with large sets of permutation patterns.
Sherry H F Yan
exaly   +5 more sources

Enumeration of Dumont permutations avoiding certain four-letter patterns [PDF]

open access: yesDiscrete Mathematics & Theoretical Computer Science, 2021
In this paper, we enumerate Dumont permutations of the fourth kind avoiding or containing certain permutations of length 4. We also conjecture a Wilf-equivalence of two 4-letter patterns on Dumont permutations of the first kind.
Alexander Burstein, Opel Jones
doaj   +1 more source

Radiometric Constraints on the Timing, Tempo, and Effects of Large Igneous Province Emplacement

open access: yesGeophysical Monograph Series, Page 27-82., 2021

Exploring the links between Large Igneous Provinces and dramatic environmental impact

An emerging consensus suggests that Large Igneous Provinces (LIPs) and Silicic LIPs (SLIPs) are a significant driver of dramatic global environmental and biological changes, including mass extinctions.
Jennifer Kasbohm   +2 more
wiley  

+2 more sources

The Rearrangement Conjecture [PDF]

open access: yesDiscrete Mathematics & Theoretical Computer Science, 2014
The Rearrangement Conjecture states that if two words over $\mathbb{P}$ are Wilf-equivalent in the factor order on $\mathbb{P}^{\ast}$ then they are rearrangements of each other.
Jay Pantone, Vincent Vatter
doaj   +1 more source

Enumeration of Stack-Sorting Preimages via a Decomposition Lemma [PDF]

open access: yesDiscrete Mathematics & Theoretical Computer Science, 2021
We give three applications of a recently-proven "Decomposition Lemma," which allows one to count preimages of certain sets of permutations under West's stack-sorting map $s$.
Colin Defant
doaj   +1 more source

Pattern avoidance in partial permutations [PDF]

open access: yes, 2011
Motivated by the concept of partial words, we introduce an analogous concept of partial permutations. A partial permutation of length n with k holes is a sequence of symbols $\pi = \pi_1\pi_2 ...
Claesson, A.   +3 more
core   +4 more sources

Consecutive Patterns in Inversion Sequences [PDF]

open access: yesDiscrete Mathematics & Theoretical Computer Science, 2019
An inversion sequence of length $n$ is an integer sequence $e=e_{1}e_{2}\dots e_{n}$ such that $0\leq e_{i}
Juan S. Auli, Sergi Elizalde
doaj   +1 more source

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