English

Oscillations in weighted arithmetic sums

Number Theory 2020-12-15 v2

Abstract

We examine oscillations in a number of sums of arithmetic functions involving Ω(n)\Omega(n), the total number of prime factors of nn, and ω(n)\omega(n), the number of distinct prime factors of nn. In particular, we examine oscillations in Sα(x)=nx(1)nΩ(n)/nαS_\alpha(x) = \sum_{n\leq x} (-1)^{n - \Omega(n)}/n^\alpha and in Hα(x)=nx(1)ω(n)/nαH_\alpha(x) = \sum_{n\leq x} (-1)^{\omega(n)}/n^{\alpha} for α[0,1]\alpha\in[0,1], and in W(x)=nx(2)Ω(n)W(x)=\sum_{n\leq x} (-2)^{\Omega(n)}. We show for example that each of the inequalities S0(x)<0S_0(x)<0, S0(x)>3.3xS_0(x)>3.3\sqrt{x}, S1(x)>0S_1(x)>0, and S1(x)x<3.3S_1(x)\sqrt{x}<-3.3 is true infinitely often, disproving some hypotheses of Sun.

Keywords

Cite

@article{arxiv.2007.14537,
  title  = {Oscillations in weighted arithmetic sums},
  author = {Michael J. Mossinghoff and Timothy S. Trudgian},
  journal= {arXiv preprint arXiv:2007.14537},
  year   = {2020}
}

Comments

To appear in Int. J. Number Theory

R2 v1 2026-06-23T17:28:50.350Z