A new theorem on the prime-counting function
Abstract
For $x>0$ let $\pi(x)$ denote the number of primes not exceeding $x$. For integers $a$ and $m>0$, we determine when there is an integer $n>1$ with $\pi(n)=(n+a)/m$. In particular, we show that for any integers $m>2$ and $a\le\lceil e^{m-1}/(m-1)\rceil$ there is an integer $n>1$ with $\pi(n)=(n+a)/m$. Consequently, for any integer $m>4$ there is a positive integer $n$ with $\pi(mn)=m+n$. We also pose several conjectures for further research; for example, we conjecture that for each $m=1,2,3,\ldots$ there is a positive integer $n$ such that $m+n$ divides $p_m+p_n$, where $p_k$ denotes the $k$-th prime.
- Publication:
-
arXiv e-prints
- Pub Date:
- September 2014
- DOI:
- 10.48550/arXiv.1409.5685
- arXiv:
- arXiv:1409.5685
- Bibcode:
- 2014arXiv1409.5685S
- Keywords:
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- Mathematics - Number Theory;
- Mathematics - Combinatorics;
- 11A41;
- 11N05;
- 05A15;
- 11A25;
- 11B39;
- 11B75
- E-Print:
- 10 pages