Saved in:
Bibliographic Details
Main Author: Hopkins, Sam
Format: Preprint
Published: 2025
Subjects:
Online Access:https://arxiv.org/abs/2510.22385
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866914586244939776
author Hopkins, Sam
author_facet Hopkins, Sam
contents In this note, we introduce two $t$-analogues $I_n(q,t)$ and $\widetilde{I}_n(q,t)$ of the tree inversion enumerator $I_n(q)$. Although similar, $I_n(q,t)$ and $\widetilde{I}_n(q,t)$ are different. But they both seem to have interesting properties. In particular, we conjecture that their $q=-1$ specializations give two different, natural refinements of the zigzag numbers counting alternating permutations.
format Preprint
id arxiv_https___arxiv_org_abs_2510_22385
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Two $t$-analogues of the tree inversion enumerator
Hopkins, Sam
Combinatorics
In this note, we introduce two $t$-analogues $I_n(q,t)$ and $\widetilde{I}_n(q,t)$ of the tree inversion enumerator $I_n(q)$. Although similar, $I_n(q,t)$ and $\widetilde{I}_n(q,t)$ are different. But they both seem to have interesting properties. In particular, we conjecture that their $q=-1$ specializations give two different, natural refinements of the zigzag numbers counting alternating permutations.
title Two $t$-analogues of the tree inversion enumerator
topic Combinatorics
url https://arxiv.org/abs/2510.22385