Elsevier

Discrete Applied Mathematics

Volume 181, 30 January 2015, Pages 201-208
Discrete Applied Mathematics

Some results on the avoidance of vincular patterns by multisets

https://doi.org/10.1016/j.dam.2014.10.011Get rights and content
Under an Elsevier user license
open archive

Abstract

Vincular or dashed patterns resemble classical patterns except that some of the letters within an occurrence must satisfy an adjacency requirement. In this paper, we show some general equivalences concerning the avoidance of vincular patterns by multiset permutations. We prove our results by defining bijections between various avoidance classes that preserve the number of occurrences of each letter. As a consequence, we obtain for multiset permutations the complete Wilf-classification of patterns of type (2,1,1), which also yields the complete classification for compositions and k-ary words when taken with numerical evidence.

Keywords

Vincular patterns
Pattern avoidance
Multiset permutation

Cited by (0)