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

