[Math] $(\mathbb Z_6,+)$ is isomorphic to a group of permutations that is a subgroup of $S_n$ for some $n$.

abstract-algebragroup-isomorphismgroup-theorypermutations

Here is my question :

Find $n$ such that $(\mathbb Z_6,+)$ is isomorphic to a group of permutations that is a subgroup of $S_n$.

I thought the answer would be $S_3$ but it turns out that $S_3$ is not abelian. Now I'm completely lost.

Any help would be appreciated.

Best Answer

Since $(\mathbb Z_6,+)$ is a cyclic group of order $6$, you need to find an element of order $6$ in $S_n$.

$S_3$ does not have an element of order $6$. Nor does $S_4$.

$S_6$ clearly does: the $6$-cycle $(123456)$.

Perhaps surprisingly, so does $S_5$, even though it's not a $6$-cycle: $(12)(345)$.