# Consecutive Patterns in Inversion Sequences

## TL;DR

This paper systematically studies consecutive pattern avoidance in inversion sequences, providing enumeration results, exploring Wilf equivalence, and classifying patterns up to length 4.

## Contribution

It introduces the first comprehensive analysis of consecutive pattern avoidance in inversion sequences, including enumeration, Wilf equivalence, and classification for patterns up to length 4.

## Key findings

- Enumeration of inversion sequences avoiding length 3 patterns
- Generalization to arbitrary pattern lengths
- Classification of patterns up to length 4 by Wilf equivalence

## Abstract

An inversion sequence of length $n$ is an integer sequence $e=e_{1}e_{2}\dots e_{n}$ such that $0\leq e_{i}<i$ for each $i$. Corteel--Martinez--Savage--Weselcouch and Mansour--Shattuck began the study of patterns in inversion sequences, focusing on the enumeration of those that avoid classical patterns of length 3. We initiate an analogous systematic study of consecutive patterns in inversion sequences, namely patterns whose entries are required to occur in adjacent positions. We enumerate inversion sequences that avoid consecutive patterns of length 3, and generalize some results to patterns of arbitrary length. Additionally, we study the notion of Wilf equivalence of consecutive patterns in inversion sequences, as well as generalizations of this notion analogous to those studied for permutation patterns. We classify patterns of length up to 4 according to the corresponding Wilf equivalence relations.