Question 45
Are there infinitely many pairs $(a, b)$ of positive integers such that
$$
a \mid b^2 + 1 \quad \text{and} \quad b \mid a^2 + 1?
$$
$$
a \mid b^2 + 1 \quad \text{and} \quad b \mid a^2 + 1?
$$
MathNet 2026 — Part 06 Question 45
Math Olympiad Vault · MathNet 2026 — Part 06