Problem 361

Erdős Problem #361: declared status 'open'. Formalized: yes. Let $c>0$ and $n$ be some large integer. What is the size of the largest $A\subseteq \{1,\ldots,\lfloor cn\rfloor\}$ such that $n$ is not a sum of a subset of $A$? Does this depend on $n$ in an irregular way? Prize: no. Tags: number theory.