Counting Number

A positive integer: 1, 2, 3, 4, ... (OEIS A000027), also called a natural number. However, zero (0) is sometimes also included in the list of counting numbers. Due to lack of standard terminology, the following terms are recommended in preference to "counting number," "natural number," and "whole number."

set	name	symbol
..., , , 0, 1, 2, ...	integers	Z
1, 2, 3, 4, ...	positive integers	Z+
0, 1, 2, 3, 4, ...	nonnegative integers	Z*
0, , , , , ...	nonpositive integers
, , , , ...	negative integers	Z-