Problem 901

Erdős Problem #901: declared status 'open'. Formalized: no. Let $m(n)$ be minimal such that there is an $n$-uniform hypergraph with $m(n)$ edges which is $3$-chromatic. Estimate $m(n)$. Current best: It is known that $m(2)=3$, $m(3)=7$, and $m(4)=23$. Erd\H{o}s proved$$2^n \ll m(n) \ll n^2 2^n$$(the lower bound in [Er63b] and the upper bound in [Er64e]). Prize: no. Tags: combinatorics, hypergraphs.