To prove that $R(3,3,3)>16$, I need to build an example of 3-coloring of $K_{16}$ which contains no monochromatic triangles.
Can anyone help me finding it?
Note : in this link I found that it has to do something with Petersen graph.
2026-03-27 06:56:52.1774594612
Construct a 3-coloring of $K_{16}$ with no monochromatic triangle
1k Views Asked by Bumbble Comm https://math.techqa.club/user/bumbble-comm/detail At
1
Take the 16 elements of the Galois field $\mathbb F_{16}$ as vertices and color the edge connecting $i$ to $j$ with the class of $i-j$ in $\mathbb F_{16}^\times/\mathbb F_{16}^{\times 3}$. Since there are 5 cubes in the field, there are 3 classes in this quotient.
Working this out with Mathematica gives me this coloring table for the edges:
And a (useless) picture:
For reference, I computed the matrix as follows: