Erdős Problem 635

### What is the conjecture

https://www.erdosproblems.com/635

Let $t\geq 1$ and $A\subseteq \\{1,\ldots,N\\}$ be such that whenever $a,b\in A$ with $b-a\geq t$ we have $b-a\nmid b$. How large can $\lvert A\rvert$ be? Is it true that
$$\lvert A\rvert \leq \left(\frac{1}{2}+o_t(1)\right)N?$$

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