MathDB
Classical NT in XMO

Source: XMO2024

April 30, 2024
number theory

Problem Statement

Let pp be a prime number and kk is a integer with p2k1p|2^k-1 for a{1,2,,p1}a\in \{ 1,2,\ldots,p-1\} , let mam_{a} be the only element that satisfies pama1p|am_{a}-1 and define Ta={x{1,2,p1}{maxpxap}<12T_{a}= \{ x \in \{1,2,\ldots p-1\} | \{ \frac {m_{a}x}{p} - \frac {x}{ap} \} < \frac{1}{2}and there exists integer y satisfying p | x-y^k+1k+1} \} Try to proof that there exists an integer mm and integers 1a1<a2<<amp11 \le a_1 <a_2< \ldots < a_{m} \le p-1 satisfying Ta1=Ta2==Tam=m |T_{a_1}| = |T_{a_2}| = \ldots = |T_{a_{m}}| = m