didericis
256cbbf90a
Exhaustive enumeration at order 28 finished with exactly four maximal planar graphs of minimum degree 5 lacking a plane diamond coloring, out of 1,204,737 total. Adds the fourth counterexample's canonical graph6 string and updates the figure caption. Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
