English

Integers with small digits in multiple bases

Number Theory 2025-09-04 v1 Combinatorics

Abstract

We show that, for any r1r\geq 1, if g1,,grg_1,\ldots,g_r are distinct coprime integers, sufficiently large depending only on rr, then for any ϵ>0\epsilon>0 there are infinitely many integers nn such that all but ϵlogn\epsilon \log n of the digits of nn are gi/2\leq g_i/2 in base gig_i for all 1ir1\leq i\leq r. In other words, for any fixed large bases, there are infinitely many nn such that almost all of the digits of nn are small in all bases simultaneously. This is both a quantitative and qualitative improvement over previous work of Croot, Mousavi, and Schmidt. As a consequence, we obtain a weak answer to a conjecture of Graham concerning divisibility of (2nn)\binom{2n}{n}.

Keywords

Cite

@article{arxiv.2509.02835,
  title  = {Integers with small digits in multiple bases},
  author = {Thomas F. Bloom and Ernie Croot},
  journal= {arXiv preprint arXiv:2509.02835},
  year   = {2025}
}

Comments

23 pages

R2 v1 2026-07-01T05:18:23.014Z