The question results from an idea I got in the proof of countable union of countable sets. As usual, the set of natural numbers is $\mathbb{N}=\{1, 2, \cdots\}$
So in that case, the question of countable union basically boils down to finding a bijection between $\mathbb{N}$ and $\mathbb{N}^2$. My question is whether it is possible to define a bijection between $\mathbb{N}$ and $\mathbb{N}^n$ for any $n\in\mathbb{N}$.
