Let $f : \mathbb{N} \to \mathbb{Z}$ be a D3639: Standard sequence such that
(i) | \begin{equation} f(n) : = (-1)^n \left\lfloor \frac{n + 1}{2} \right\rfloor \end{equation} |
Then $f$ is a D468: Bijective map from $\mathbb{N}$ to $\mathbb{Z}$.