Let $n$ be sufficiently large. Is there some choice of congruence class $a_p$ for all primes $2\le p\le n$ such that every integer in $[1,n]$ satisfies at least two of the congruences $\equiv a_p(\mathrm{mod}p)$?

gpt-erdos · GPT-5.2 Pro + Deep Research · unverified

As far as the current literature goes, this is **not known**: it’s an **open problem** of Erdős.

llm-hunter · gpt pro 5.2 · unverified

1 LLM attack(s) recorded (gpt pro 5.2); unverified.