The most probable order of a random permutation
Combinatorics
2025-10-14 v1 Group Theory
Abstract
Given positive integers and , let be the probability that a uniform random permutation of has order exactly . We show that, as , the maximum of over all is asymptotic to , the probability of an -cycle. Furthermore, for sufficiently large , we show that the maximum is attained precisely if is the least positive integer divisible by all positive integers less than or equal to . This answers a question of Acan, Burnette, Eberhard, Schmutz and Thomas, originally attributed to work of Erd\H{o}s and Tur\'an from 1968.
Cite
@article{arxiv.2510.11698,
title = {The most probable order of a random permutation},
author = {Adrian Beker},
journal= {arXiv preprint arXiv:2510.11698},
year = {2025}
}
Comments
8 pages