English

Sharp Bounds for Sets with Distinct Subset Products

Combinatorics 2026-03-02 v2 Number Theory

Abstract

Let A[N]A\subseteq [N] be such that for any pair of distinct subsets B,CAB,C\subset A, the products bBb\prod_{b\in B}b and cCc\prod_{c\in C}c are distinct. We prove that Aπ(N)+π(N1/2)+o(π(N1/2))|A|\leq \pi(N)+\pi(N^{1/2})+o(\pi(N^{1/2})), where π\pi is the prime counting function, answering a question of Erd\H{o}s.

Keywords

Cite

@article{arxiv.2501.02695,
  title  = {Sharp Bounds for Sets with Distinct Subset Products},
  author = {Rushil Raghavan},
  journal= {arXiv preprint arXiv:2501.02695},
  year   = {2026}
}

Comments

13 pages, 4 figures. Updated to match published version

R2 v1 2026-06-28T20:57:04.337Z