A new theorem on the primecounting 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 $a\le\lceil e^{m1}/(m1)\rceil$ 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 eprints
 Pub Date:
 September 2014
 arXiv:
 arXiv:1409.5685
 Bibcode:
 2014arXiv1409.5685S
 Keywords:

 Mathematics  Number Theory;
 Mathematics  Combinatorics;
 11A41;
 11N05;
 05A15;
 11A25;
 11B39;
 11B75
 EPrint:
 10 pages