Erdős Problem 1076

### What is the conjecture

https://www.erdosproblems.com/1076

Let $k\geq 5$ and let $\mathcal{F}_k$ be the family of all $3$-uniform hypergraphs with $k$ vertices and $k-2$ edges. Is it true that
$$\mathrm{ex}_3(n,\mathcal{F}_k)\sim \frac{n^2}{6}?$$

Status: open

### Choose either option
- [ ] I plan on working on this conjecture
- [x] This issue is up for grabs: I would like to see this conjecture added by somebody else

Start with the conjecture statement at erdosproblems.com/1076 and inspect existing formalized Erdős problems in the repository for the appropriate entry point. Done means the stated conjecture is added to the collection in a checked formalization, with any relevant repository checks passing.

Written by the indexing model from the issue text.