$k$-pop stack sortable permutations and $2$-avoidance
Combinatorics
2019-12-17 v2
Abstract
We consider permutations sortable by passes through a deterministic pop stack. We show that for any the set is characterised by finitely many patterns, answering a question of Claesson and Gu{\dh}mundsson. Our characterisation demands a more precise definition than in previous literature of what it means for a permutation to avoid a set of barred and unbarred patterns. We propose a new notion called \emph{-avoidance}.
Cite
@article{arxiv.1911.03104,
title = {$k$-pop stack sortable permutations and $2$-avoidance},
author = {Murray Elder and Yoong Kuan Goh},
journal= {arXiv preprint arXiv:1911.03104},
year = {2019}
}
Comments
10 pages, 4 figures. Simpler notion of 2-avoidance introduced, replacing the more complicated (but equivalent) PB-avoidance in the previous version