English

Translated sums of primitive sets

Number Theory 2023-05-09 v2 Combinatorics

Abstract

The Erd\H{o}s primitive set conjecture states that the sum f(A)=aA1alogaf(A) = \sum_{a\in A}\frac{1}{a\log a}, ranging over any primitive set AA of positive integers, is maximized by the set of prime numbers. Recently Laib, Derbal, and Mechik proved that the translated Erd\H{o}s conjecture for the sum f(A,h)=aA1a(loga+h)f(A,h) = \sum_{a\in A}\frac{1}{a(\log a+h)} is false starting at h=81h=81, by comparison with semiprimes. In this note we prove that such falsehood occurs already at h=1.04h= 1.04\cdots, and show this translate is best possible for semiprimes. We also obtain results for translated sums of kk-almost primes with larger kk.

Keywords

Cite

@article{arxiv.2110.10146,
  title  = {Translated sums of primitive sets},
  author = {Jared Duker Lichtman},
  journal= {arXiv preprint arXiv:2110.10146},
  year   = {2023}
}

Comments

incorporated referee comments, corrected $h_\infty = .803...$, and cited earlier 1986 reference to the Erd\H{o}s primitive set conjecture

R2 v1 2026-06-24T07:01:22.936Z