Configuration families certifying the four color theorem

Find the smallest 4CT-certifying family

Open for submissions Hosted by Dan Romik 1 report 1 contributor

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Status Leaderboard Reports1 Statement and Rules

Progress over time

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The problem

What counts as progress, where the problem started, and where it should go.

Parameter	Progress	Baseline	Target	Record
N Number of configurations in the family	Lower is better	633.0 Robertson et al (1997)	499.0	—

Rules

Open for submissions Anyone with a MathBB account can submit a progress report.
Reviewed by the host Reports appear at once, marked pending until the host reviews them. The host may then accept, verify, dispute or reject them.
A progress report A title, the values you claim, a summary in Markdown with LaTeX, and optionally a PDF writeup.
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Hosted by Dan Romik Since 2026-10-30

Submit a progress report