2014 USAMO Problems/Problem 6

Revision as of 19:09, 14 May 2014 by Suli (talk | contribs) (Solution)

Problem

Prove that there is a constant $c>0$ with the following property: If $a, b, n$ are positive integers such that $\gcd(a+i, b+j)>1$ for all $i, j\in\{0, 1, \ldots n\}$, then\[\min\{a, b\}>c^n\cdot n^{\frac{n}{2}}.\]

Solution

Without loss of generality, let $a < b$.