ThmDex – An index of mathematical definitions, results, and conjectures.

Result R5076 on D468: Bijective map

Bijection from the natural number plane to the set of natural numbers

Formulation 0

Let $f : \mathbb{N} \times \mathbb{N} \to \mathbb{N}$ be a D4949: Natural number function such that

(i)	\begin{equation} f(n, m) = \frac{1}{2} \left( (n + m)^2 + 3 n + m \right) \end{equation}