Two permutations in a class are Wilf-equivalent if, for every size, $n$, the number of permutations in the class of size $n$ containing each of them is the same. Those infinite classes that have only one equivalence class in each size for this relation are characterised provided either that they avoid at least one permutation of size 3, or at least three permutations of size 4.

Source : oai:arXiv.org:1904.05500

Volume: Vol. 21 no. 2, Permutation Patters 2018

Published on: November 4, 2019

Submitted on: April 12, 2019

Keywords: Mathematics - Combinatorics,Computer Science - Discrete Mathematics,05A05, 05A15, 05-04