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A SIEVE PROBLEM AND ITS APPLICATION

Published online by Cambridge University Press:  27 September 2016

Andreas Weingartner*
Affiliation:
Department of Mathematics, Southern Utah University, 351 West University Boulevard, Cedar City, UT 84720, U.S.A. email weingartner@suu.edu
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Abstract

Let $\unicode[STIX]{x1D703}$ be an arithmetic function and let ${\mathcal{B}}$ be the set of positive integers $n=p_{1}^{\unicode[STIX]{x1D6FC}_{1}}\cdots p_{k}^{\unicode[STIX]{x1D6FC}_{k}}$ which satisfy $p_{j+1}\leqslant \unicode[STIX]{x1D703}(p_{1}^{\unicode[STIX]{x1D6FC}_{1}}\cdots p_{j}^{\unicode[STIX]{x1D6FC}_{j}})$ for $0\leqslant j<k$. We show that ${\mathcal{B}}$ has a natural density, provide a criterion to determine whether this density is positive, and give various estimates for the counting function of ${\mathcal{B}}$. When $\unicode[STIX]{x1D703}(n)/n$ is non-decreasing, the set ${\mathcal{B}}$ coincides with the set of integers $n$ whose divisors $1=d_{1}<d_{2}<\cdots <d_{\unicode[STIX]{x1D70F}(n)}=n$ satisfy $d_{j+1}\leqslant \unicode[STIX]{x1D703}(d_{j})$ for $1\leqslant j<\unicode[STIX]{x1D70F}(n)$.

Type
Research Article
Copyright
Copyright © University College London 2016 

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References

Cheer, A. Y. and Goldston, D. A., A differential delay equation arising from the sieve of Eratosthenes. Math. Comp. 55 1990, 129141.CrossRefGoogle Scholar
Pomerance, C., Thompson, L. and Weingartner, A., On integers $n$ for which $X^{n}-1$ has a divisor of every degree. Acta Arith. (to appear), doi:10.4064/aa8354-6-2016.CrossRefGoogle Scholar
Rosser, J. B. and Schoenfeld, L., Approximate formulas for some functions of prime numbers. Illinois J. Math. 6 1962, 6494.Google Scholar
Saias, E., Entiers à diviseurs denses 1. J. Number Theory 62 1997, 163191.CrossRefGoogle Scholar
Tenenbaum, G., Sur un problème de crible et ses applications. Ann. Sci. Éc. Norm. Supér. (4) 19 1986, 130.Google Scholar
Thompson, L., Polynomials with divisors of every degree. J. Number Theory 132 2012, 10381053.CrossRefGoogle Scholar
Thompson, L., Variations on a question concerning the degrees of divisors of x n - 1. J. Théor. Nombres Bordeaux 26 2014, 253267.CrossRefGoogle Scholar
Weingartner, A., Practical numbers and the distribution of divisors. Q. J. Math. 66 2015, 743758.Google Scholar