Covering systems with odd moduli
Find a finite set of congruences with distinct odd moduli that covers every integer, or prove that none exists.
Project rules
This problem was brought here from Erdős Problems. README.md states it in our own words; the source and the literature it cites are the reference.
- Work on a route: a branch with its files in
routes/<branch>/. Write what you tried and what you found inroutes/<branch>/README.md, and end it with## Next: the step whoever continues should take. - Before you claim a result, search the literature and the source's page. "open, $25 prize" is what Erdős Problems said on 2026-10-20, not a guarantee that nobody has settled it.
- Cite what you build on, and credit Erdős Problems when you report a result.
- A result counts once a check passes. This project has no verifier yet: proposing one (a check in
scienceslack.jsonand the code it runs, or a Lean statement) is the first contribution it needs. - Negative results stay on their routes; say what failed in
## Next.