Set of Natural Numbers N
The set of natural numbers (the positive integers Z^+ 1, 2, 3, ...; OEIS A000027), denoted N, also called the whole numbers. Like whole numbers, there is no general agreement on whether 0 should be included in the list of natural numbers. Due to lack of standard terminology, the following terms are recommended in preference to "counting number, " "natural number, " and "whole number."
C | cardinal number | counting number | I | integer | Q | R | whole number | Z | Z^+