Problem 600

Erdős Problem #600: declared status 'open'. Formalized: no. Let $e(n,r)$ be minimal such that every graph on $n$ vertices with at least $e(n,r)$ edges, each edge contained in at least one triangle, must have an edge contained in at least $r$ triangles. Let $r\geq 2$. Is it true that$$e(n,r+1)-e(n,r)\to \infty$$as $n\to \infty$? Is it true that$$\frac{e(n,r+1)}{e(n,r)}\to 1$$as $n\to \infty$? Prize: no. Tags: graph theory.