Question 2
Let $n$ be a positive integer.
Determine the size of the largest subset of $\{ -n, -n+1, \ldots, n-1, n\}$
which does not contain three elements $a$, $b$, $c$ (not necessarily distinct)
satisfying $a+b+c=0$.
Proposed by Kiran Kedlaya, Tewordos Amdeberhan (credit in the supplied third-party notes).
Determine the size of the largest subset of $\{ -n, -n+1, \ldots, n-1, n\}$
which does not contain three elements $a$, $b$, $c$ (not necessarily distinct)
satisfying $a+b+c=0$.
Proposed by Kiran Kedlaya, Tewordos Amdeberhan (credit in the supplied third-party notes).