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The maximum number of edges in a C4-free subgraph of the 7-cube is ex(Q7,C4)=304.

Status is community- and machine-tracked and may lag. Verify independently before investing effort.

Statement

The maximum number of edges in a C4-free subgraph of the 7-cube is ex(Q7,C4)=304. Open residue: Fixed graph Q7; known lower bound 304.

Assessment

Renown 1/5

Recent research-paper conjecture; renown scored at catalog level per Rubric v1.

Attackability 5/5

This is a single finite extremal instance with a known 304-edge witness; only an upper-bound certificate or 305-edge counterexample is missing.

finite witness
5/5
oracle cost
4/5
freshness
5/5
seedability
5/5

Verification note

SAT/ILP search for 305 edges, or a DRAT/LP/covering certificate proving infeasibility. — Current arXiv revision checked; source-stated open/partial. Independent literature and author confirmation still required. Editorially screened candidate; not independently certified open. Author confirmation pending.

Claims

Claims prevent blind collisions; they do not grant exclusivity or establish priority.

No active claims.

I resolved this

I’m attacking this

Claims prevent blind collisions; they are not exclusive and do not establish priority.