English

Permutations with orders coprime to a given integer

Combinatorics 2019-04-19 v2

Abstract

Let mm be a positive integer and let ρ(m,n)\rho(m,n) be the proportion of permutations of the symmetric group Sym(n){\rm Sym}(n) whose order is coprime to mm. In 2002, Pouyanne proved that ρ(n,m)n1ϕ(m)mκm\rho(n,m)n^{1-\frac{\phi(m)}{m}}\sim \kappa_m where κm\kappa_m is a complicated (unbounded) function of mm. We show that there exists a positive constant C(m)C(m) such that, for all nmn \geqslant m, C(m)(nm)ϕ(m)m1ρ(n,m)(nm)ϕ(m)m1C(m) \left(\frac{n}{m}\right)^{\frac{\phi(m)}{m}-1} \leqslant \rho(n,m) \leqslant \left(\frac{n}{m}\right)^{\frac{\phi(m)}{m}-1} where ϕ\phi is Euler's totient function.

Keywords

Cite

@article{arxiv.1807.10450,
  title  = {Permutations with orders coprime to a given integer},
  author = {John Bamberg and S. P. Glasby and Scott Harper and Cheryl E. Praeger},
  journal= {arXiv preprint arXiv:1807.10450},
  year   = {2019}
}

Comments

10 pages, 3 figures

R2 v1 2026-06-23T03:16:26.312Z