Question 24
Find all positive integers $n$ such that
$$
(n^2 + 11n - 4) \cdot n! + 33 \cdot 13^n + 4
$$
is a perfect square.
$$
(n^2 + 11n - 4) \cdot n! + 33 \cdot 13^n + 4
$$
is a perfect square.
MathNet 2014 Question 24
Math Olympiad Vault · MathNet 2014