# A question regarding Bertrand's postulate (Erdős proof)...

• Jul 20th 2011, 01:09 PM
Also sprach Zarathustra
A question regarding Bertrand's postulate (Erdős proof)...
Proof of Bertrand's postulate - Wikipedia, the free encyclopedia

I don't understand why the product in red underline less than the product in the red box in the attachment.

Lemma 3 insures it. If $p>\sqrt{2n}$ then $R(p,n)$ is 1 or 0.