English

Unit fractions with shifted prime denominators

Number Theory 2026-01-14 v1

Abstract

We prove that any positive rational number is the sum of distinct unit fractions with denominators in {p1:p prime}\{p-1 : p\textrm{ prime}\}. The same conclusion holds for the set {ph:p prime}\{p-h : p\textrm{ prime}\} for any hZ\{0}h\in\mathbb{Z}\backslash\{0\}, provided a necessary congruence condition is satisfied. We also prove that this is true for any subset of the primes of relative positive density, provided a necessary congruence condition is satisfied.

Keywords

Cite

@article{arxiv.2305.02689,
  title  = {Unit fractions with shifted prime denominators},
  author = {Thomas F. Bloom},
  journal= {arXiv preprint arXiv:2305.02689},
  year   = {2026}
}

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9 pages