Proof Writing & Problem Solving · Superchallenge problem

There are $n$ stones placed around a circle, at equally spaced points. Two players take turns; a move removes either one stone, or two stones that sit at NEIGHBOURING points of the circle (both still present). Removed stones are not replaced, so their points stay empty. The player who takes the last stone wins. For how many $n$ with $1 \le n \le 30$ can the SECOND player force a win?