This is Kolakosiki sequence: $1,2,2,1,1,2,1,2,2,1,2,2,1,1,2,1,1,2,2,1……$. This sequence consists of $1$ and $2$, and its first term equals $1$. Besides, if you see adjacent and equal terms as one group, you will get $1,22,11,2,1,22,1,22,11,2,11,22,1……$. Count number of terms in every group, you will get the sequence itself. Now, the sequence can be uniquely determined. Please tell HazelFan its $n$th element.