English

Extremal orders of compositions of certain arithmetical functions

Number Theory 2008-09-01 v2

Abstract

We study the exact extremal orders of compositions f(g(n))f(g(n)) of certain arithmetical functions, including the functions σ(n)\sigma(n), ϕ(n)\phi(n), σ(n)\sigma^*(n) and ϕ(n)\phi^*(n), representing the sum of divisors of nn, Euler's function and their unitary analogues, respectively. Our results complete, generalize and refine known results.

Keywords

Cite

@article{arxiv.0802.1106,
  title  = {Extremal orders of compositions of certain arithmetical functions},
  author = {József Sándor and László Tóth},
  journal= {arXiv preprint arXiv:0802.1106},
  year   = {2008}
}

Comments

improved and corrected final version

R2 v1 2026-06-21T10:10:44.877Z