describe all $ n \in \mathbb{N}$ such that $ -1 \in \left \langle 2 \right \rangle \leq (\mathbb{Z}/n\mathbb{Z})^x $ Hi, I would like to describe (in a lower level of abstraction) the set $ N = \left \{n \in \mathbb{N} : -1 \in \left \langle 2 \right \rangle \leq (\mathbb{Z}/n\mathbb{Z})^x \right \} $ . ClearlyRead more