Question 50
Félix wants to colour the integers from $1$ to $2023$ so that if $a, b$ are two distinct integers between $1$ and $2023$ and $a$ divides $b$, then $a$ and $b$ have different colours. What is the minimum number of colours Félix needs?
Math Olympiad Vault · MathNet 2023-part-02 — 191 problems (EN–VI)