English

An assortment of problems in permutation patterns: unimodality, equivalence, derangements, and sorting

Combinatorics 2026-02-27 v2

Abstract

We collect open problems in permutation patterns on four themes: rank-unimodality in the permutation pattern poset, Wilf-equivalence and shape-Wilf-equivalence, the enumeration of derangements in permutation classes, and sorting by stacks in series, generalized stacks, and restricted containers (C-machines).

Keywords

Cite

@article{arxiv.2602.16355,
  title  = {An assortment of problems in permutation patterns: unimodality, equivalence, derangements, and sorting},
  author = {Vincent Vatter},
  journal= {arXiv preprint arXiv:2602.16355},
  year   = {2026}
}
R2 v1 2026-07-01T10:41:06.944Z