Problem 576

Erdős Problem #576: declared status 'open'. Formalized: no. Let $Q_k$ be the $k$-dimensional hypercube graph (so that $Q_k$ has $2^k$ vertices and $k2^{k-1}$ edges). Determine the behaviour of$$\mathrm{ex}(n;Q_k).$$ Prize: no. Tags: graph theory, turan number.