Proof Writing & Problem Solving · Challenge problem

For how many integers $n$ with $1 \le n \le 100$ is $\left\lfloor \dfrac{n}{2} \right\rfloor + \left\lfloor \dfrac{n}{3} \right\rfloor + \left\lfloor \dfrac{n}{6} \right\rfloor = n - 1$?