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Related papers: Refined sign-balance on 321-avoiding permutations

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We consider a large family of equivalence relations on permutations in Sn that generalise those discovered by Knuth in his study of the Robinson-Schensted correspondence. In our most general setting, two permutations are equivalent if one…

Combinatorics · Mathematics 2011-11-17 Steven Linton , James Propp , Tom Roby , Julian West

We present a simplified variant of Biane's bijection between permutations and 3-colored Motzkin paths with weight that keeps track of the inversion number, excedance number and a statistic so-called depth of a permutation. This generalizes…

Combinatorics · Mathematics 2024-06-25 Sen-Peng Eu , Tung-Shan Fu , Yuan-Hsun Lo

We continue our study of a new boundedness condition for affine permutations, motivated by the fruitful concept of periodic boundary conditions in statistical physics. We focus on bounded affine permutations of size $N$ that avoid the…

Combinatorics · Mathematics 2022-01-13 Neal Madras , Justin M. Troyka

We show that the distribution of the major index over the set of involutions in S_n that avoid the pattern 321 is given by the q-analogue of the n-th central binomial coefficient. The proof consists of a composition of three non-trivial…

Combinatorics · Mathematics 2014-07-25 Marilena Barnabei , Flavio Bonetti , Sergi Elizalde , Matteo Silimbani

Bouvel and Pergola introduced the notion of minimal permutations in the study of the whole genome duplication-random loss model for genome rearrangements. Let $\mathcal{F}_d(n)$ denote the set of minimal permutations of length $n$ with $d$…

Combinatorics · Mathematics 2010-11-01 William Y. C. Chen , Cindy C. Y. Gu , Kevin J. Ma

In this paper, we consider two sets of pattern-avoiding ascent sequences: those avoiding both 201 and 210 and those avoiding 0021. In each case we show that the number of such ascent sequences is given by the binomial convolution of the…

Combinatorics · Mathematics 2014-10-29 Lara K. Pudwell

Let the sign of a standard Young tableau be the sign of the permutation you get by reading it row by row from left to right, like a book. A conjecture by Richard Stanley says that the sum of the signs of all SYTs with n squares is 2^[n/2].…

Combinatorics · Mathematics 2007-05-23 Jonas Sjöstrand

This paper establishes an analogue of the Robinson--Schensted correspondence for cylindric tableaux. In particular, for any pair of positive integers $(d,L)$, we construct a bijection between permutations that avoid the patterns $d\cdots 1…

Combinatorics · Mathematics 2026-03-17 Alexander Dobner

The diagram of a 132-avoiding permutation can easily be characterized: it is simply the diagram of a partition. Based on this fact, we present a new bijection between 132-avoiding and 321-avoiding permutations. We will show that this…

Combinatorics · Mathematics 2007-05-23 Astrid Reifegerste

It is a classical result that the parity-balance of the number of weak excedances of all permutations (derangements, respectively) of length $n$ is the Euler number $E_n$, alternating in sign, if $n$ is odd (even, respectively).…

Combinatorics · Mathematics 2018-02-06 Sen-Peng Eu , Tung-Shan Fu , Hsiang-Chun Hsu , Hsin-Chieh Liao

We show that the number of signed permutations avoiding 1234 equals the number of signed permutations avoiding 2143 (also called vexillary signed permutations), resolving a conjecture by Anderson and Fulton. The main tool that we use is the…

Combinatorics · Mathematics 2020-09-07 Yibo Gao , Kaarel Hänni

It is known that, when $n$ is even, the number of permutations of $\{1,2,\dots,n\}$ all of whose cycles have odd length equals the number of those all of whose cycles have even length. Adin, Heged\H{u}s and Roichman recently found a…

Combinatorics · Mathematics 2025-04-08 Sergi Elizalde

We consider a random permutation drawn from the set of 321-avoiding permutations of length $n$ and show that the number of occurrences of another pattern $\sigma$ has a limit distribution, after scaling by $n^{m+\ell}$ where $m$ is the…

Probability · Mathematics 2017-12-22 Svante Janson

We present a new approach to the problem of enumerating permutations of length n that avoid a fixed consecutive pattern of length m. We use this idea to give explicit upper and lower bounds on the number of permutations avoiding a pattern…

Combinatorics · Mathematics 2012-08-29 Guillem Perarnau

It is well-known, and was first established by Knuth in 1969, that the number of 321-avoiding permutations is equal to that of 132-avoiding permutations. In the literature one can find many subsequent bijective proofs of this fact. It turns…

Combinatorics · Mathematics 2008-05-12 Anders Claesson , Sergey Kitaev

We prove that the number of permutations which avoid 132-patterns and have exactly one 123-pattern equals (n-2)2^(n-3). We then give a bijection onto the set of permutations which avoid 123-patterns and have exactly one 132-pattern.…

Combinatorics · Mathematics 2007-05-23 Aaron Robertson

We show how the sign of a permutation can be deduced from the tableaux induced by the permutation under the Robinson-Schensted-Knuth correspondence. The result yields a simple proof of a conjecture on the squares of imbalances raised by…

Combinatorics · Mathematics 2007-05-23 Astrid Reifegerste

We introduce the notion of 321-avoiding permutations in the affine Weyl group $W$ of type $A_{n-1}$ by considering the group as a George group (in the sense of Eriksson and Eriksson). This enables us to generalize a result of Billey,…

Combinatorics · Mathematics 2007-05-23 R. M. Green

We prove that the excedance relation on permutations defined by N. Bergeron and L. Gagnon actually extends to a congruence of the lattice on alternating sign matrices. Motivated by this example, we study all lattice congruences of the…

Combinatorics · Mathematics 2026-02-23 Florent Hivert , Vincent Pilaud , Ludovic Schwob

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 $s$. We first enumerate the permutation class…

Combinatorics · Mathematics 2023-06-22 Colin Defant