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Related papers: Pattern-avoiding modified ascent sequences

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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…

Combinatorics · Mathematics 2009-11-17 Robert Parviainen

We exploit Krattenthaler's bijection between 123-avoiding permutations and Dyck paths to determine the Eulerian distribution over the set $S_n(123)$ of 123-avoiding permutations in $S_n$. In particular, we show that the descents of a…

Combinatorics · Mathematics 2009-10-07 M. Barnabei , F. Bonetti , M. Silimbani

In this paper we study the enumeration and the construction of particular binary words avoiding the pattern $1^{j+1}0^j$. By means of the theory of Riordan arrays, we solve the enumeration problem and we give a particular succession rule,…

Discrete Mathematics · Computer Science 2011-03-30 Stefano Bilotta , Donatella Merlini , Elisa Pergola , Renzo Pinzani

In this paper we prove that among the permutations of length n with i fixed points and j excedances, the number of 321-avoiding ones equals the number of 132-avoiding ones, for all given i,j<=n. We use a new technique involving diagonals of…

Combinatorics · Mathematics 2007-05-23 Sergi Elizalde

In this paper, we show that both 12312-avoiding partitions and 12321-avoiding partitions of the set $[n+1]$ are in one-to-one correspondence with Schr\"oder paths of semilength $n$ without peaks at even level. As a consequence, the refined…

Combinatorics · Mathematics 2009-03-09 Sherry H. F. Yan

Higher dimensional permutations are tuples of d-1 permutations that can be identified with a point set in a d-dimensional grid. In N. Bonichon and P.-J. Morel, {\it J. Integer Sequences} 25 (2022), several conjectures regarding the…

Combinatorics · Mathematics 2026-05-21 Thomas Muller

The study of pattern avoidance in permutations, and specifically in flattened partitions is an active area of current research. In this paper, we count the number of distinct flattened partitions over [n] avoiding a single pattern, as well…

Combinatorics · Mathematics 2020-11-17 Olivia Nabawanda , Fanja Rakotondrajao

There is a natural bijection between permutations obtainable using a stack (those avoiding the pattern 312) and permutations obtainable using a queue (those avoiding 321). This bijection is equivalent to one described by Simion and Schmidt…

Combinatorics · Mathematics 2012-02-01 Peter G. Doyle

The large Schroder numbers are known to count several classes of permutations avoiding two 4-letter patterns. Here we show they count another family of permutations, those whose left to right minima decomposition, when reversed, is…

Combinatorics · Mathematics 2012-10-25 David Callan

Pattern avoiding machines were introduced recently by Claesson, Cerbai and Ferrari as a particular case of the two-stacks in series sorting device. They consist of two restricted stacks in series, ruled by a right-greedy procedure and the…

Discrete Mathematics · Computer Science 2020-09-23 J. -L. Baril , G. Cerbai , C. Khalil , V. Vajnovszki

In 2012 B\'ona showed the rather surprising fact that the cumulative number of occurrences of the classical patterns $231$ and $213$ are the same on the set of permutations avoiding $132$, beside the pattern based statistics $231$ and $213$…

Combinatorics · Mathematics 2014-12-12 Vincent Vajnovszki

The enumeration of inversion sequences avoiding a single pattern was initiated by Corteel--Martinez--Savage--Weselcouch and Mansour--Shattuck independently. Their work has sparked various investigations of generalized patterns in inversion…

Combinatorics · Mathematics 2023-06-22 Chunyan Yan , Zhicong Lin

Building off recent work of Garg and Peng, we continue the investigation into classical and consecutive pattern avoidance in rooted forests. We prove a forest analogue of the Stanley-Wilf conjecture for avoiding a single pattern as well as…

Combinatorics · Mathematics 2023-10-05 Michael Ren

In this paper we study pattern avoidance for affine permutations. In particular, we show that for a given pattern p, there are only finitely many affine permutations in $\widetilde{S}_n$ that avoid p if and only if p avoids the pattern 321.…

Combinatorics · Mathematics 2010-11-15 Andrew Crites

Using techniques from Poisson approximation, we prove explicit error bounds on the number of permutations that avoid any pattern. Most generally, we bound the total variation distance between the joint distribution of pattern occurrences…

Combinatorics · Mathematics 2023-06-22 Harry Crane , Stephen DeSalvo

The number of even 321-avoiding permutations of length n is equal to the number of odd ones if n is even, and exceeds it by the (n-1)/2th Catalan number otherwise. We present an involution that proves a refinement of this sign-balance…

Combinatorics · Mathematics 2007-05-23 Astrid Reifegerste

There exists a bijection between one stack sortable permutations --permutations which avoid the pattern 231-- and planar trees. We define an edit distance between permutations which is coherent with the standard edit distance between trees.…

Combinatorics · Mathematics 2007-05-23 Anne Micheli , Dominique Rossin

This paper presents a bijection between ascent sequences and upper triangular matrices whose non-negative entries are such that all rows and columns contain at least one non-zero entry. We show the equivalence of several natural statistics…

Combinatorics · Mathematics 2009-09-21 Mark Dukes , Robert Parviainen

In this paper, we introduce the definitions of simsun succession, simsun cycle succession and simsun pattern. In particular, the ordinary simsun permutations are permutations avoiding simsun pattern 321. We study the descent and peak…

Combinatorics · Mathematics 2016-03-01 Shi-Mei Ma , Yeong-Nan Yeh

Inspired by Yakoubov's 2015 investigation of pattern avoiding linear extensions of the posets called combs, we study pattern avoiding linear extensions of rectangular posets. These linear extensions are closely related to standard tableaux.…

Combinatorics · Mathematics 2016-05-24 David Anderson , Eric S. Egge , Manda Riehl , Lucas Ryan , Ruth Steinke , Yuriko Vaughan