Erdős Problem 261 — qed.bot Claims, announcements and changes recorded against Erdős Problem 261. https://qed.bot/feeds/s/erdos-261.xml 2026-09-28T11:57:19Z qed.bot Fidelity regraded: Erdős Problem 261 urn:qed:change:fidelity:erdos:261:F2 2026-09-28T11:57:19Z The fidelity grade for Erdős Problem 261 moved from F0 to F2.