English

A formula for enumerating permutations with a fixed pinnacle set

Combinatorics 2020-01-22 v1

Abstract

In 2017 Davis, Nelson, Petersen, and Tenner pioneered the study of pinnacle sets of permutations and asked whether there exists a class of operations, which applied to a permutation in Sn\mathfrak{S}_n, can produce any other permutation with the same pinnacle set and no others. In this paper, we adapt a group action defined by Foata and Strehl to provide a way to generate all permutations with a given pinnacle set. From this we give a closed non-recursive formula enumerating permutations with a given pinnacle set. Thus answering a question posed by Davis, Nelson, Petersen, and Tenner.

Keywords

Cite

@article{arxiv.2001.07325,
  title  = {A formula for enumerating permutations with a fixed pinnacle set},
  author = {Alexander Diaz-Lopez and Pamela E. Harris and Isabella Huang and Erik Insko and Lars Nilsen},
  journal= {arXiv preprint arXiv:2001.07325},
  year   = {2020}
}

Comments

17 pages, 1 figure, 3 tables

R2 v1 2026-06-23T13:16:04.151Z