From: Robin Chapman <rjc@maths.ex.ac.uk>
Subject: Re: There is a prime between n and 2n for natural number n?
Date: Thu, 18 Nov 1999 08:47:14 GMT
Newsgroups: sci.math
Keywords: Bertrand's postulate

In article <38339084.7F9C0458@minjok-h.ed.kangwon.kr>,
  Sangjeong Kim <urchin@minjok-h.ed.kangwon.kr> wrote:
> Do you know simple proof of the fact that there is a prime between n and
> 2n?

This is called Bertrand's postulate. It was first proved by Chebyshev.
Paul Erdos later found a simple proof. I have put a version of the
Erdos proof on my webpage (see below) in DVI format.

--
Robin Chapman
 http://www.maths.ex.ac.uk/~rjc/rjc.html
  "`Well, I'd already done a PhD in X-Files Theory at UCLA, ...'"
    Greg Egan, _Teranesia_


Sent via Deja.com http://www.deja.com/
Before you buy.