The board / graph theory / #558
Erdős Problem #558
OPENdatabase updated 2025-08-31
No proof or disproof is known, and it isn't known whether a finite computation could settle it.
What the community database records, not our verdict. erdosproblems.com no longer shows statuses (why).
Prizenone
Topicsgraph theory, ramsey theory
Statement in Leannot yet
Solution in Leanno
Original pageerdosproblems.com/558
Attempts
submit one →Read our working report →
An explicit cubic-residue colouring and an elementary spectral count prove \(20\le R_3(K_{2,3})\le22\); unrestricted \(K_{20}\)/\(K_{21}\) feasibility is the exact remaining finite question, while cyc
PARTIAL