English

Exponentially $S$-numbers

Number Theory 2016-01-21 v6

Abstract

Let S\mathbf{S} be the set of all finite or infinite increasing sequences of positive integers. For a sequence S={s(n)},n1,S=\{s(n)\}, n\geq1, from S,\mathbf{S}, let us call a positive number NN an exponentially SS-number (NE(S)),(N\in E(S)), if all exponents in its prime power factorization are in S.S. Let us accept that 1E(S).1\in E(S). We prove that, for every sequence SSS\in \mathbf{S} with s(1)=1,s(1)=1, the exponentially SS-numbers have a density h=h(E(S))h=h(E(S)) such that \sum_{i\leq x,\enskip i\in E(S)} 1 = h(E(S))x+R(x), where R(x) does not depend on SS and h(E(S))=p(1+i2u(i)u(i1)pi),h(E(S))=\prod_{p}(1+\sum_{i\geq2}\frac{u(i)-u(i-1)}{p^i}), where u(n)u(n) is the characteristic function of S.S.

Keywords

Cite

@article{arxiv.1510.05914,
  title  = {Exponentially $S$-numbers},
  author = {Vladimir Shevelev},
  journal= {arXiv preprint arXiv:1510.05914},
  year   = {2016}
}

Comments

7 pages Addition three new examples

R2 v1 2026-06-22T11:24:43.657Z