English

The number system in rational base $3/2$ and the $3x+1$ problem

Number Theory 2025-04-21 v1

Abstract

The representation of numbers in rational base p/qp/q was introduced in 2008 by Akiyama, Frougny & Sakarovitch, with a special focus on the case p/q=3/2p/q=3/2. Unnoticed since then, natural questions related to representations in that specific base turn out to intimately involve the Collatz 3x+13x+1 function. Our purpose in this note is to expose these links and motivate further research into them.

Cite

@article{arxiv.2504.13716,
  title  = {The number system in rational base $3/2$ and the $3x+1$ problem},
  author = {Shalom Eliahou and Jean-Louis Verger-Gaugry},
  journal= {arXiv preprint arXiv:2504.13716},
  year   = {2025}
}

Comments

9 pages. To appear in Comptes Rendus. Math\'ematique. Acad\'emie des Sciences, Paris

R2 v1 2026-06-28T23:03:19.882Z