1

The number one (1)also called "unity," is the first positive integer. It is an odd number. Although the number 1 used to be considered a prime numberit requires special treatment in so many definitions and applications involving primes greater than or equal to 2 that it is usually placed into a class of its own (Wells 1986, p. 31). The number 1 is sometimes also called "unity," so the th roots of 1 are often called the th roots of unity. Fractions having 1 as a numerator are called unit fractions. If only one rootsolution, etc.exists to a given problemthe solution is called unique.

The generating function having all coefficients 1 is given by

(1)

The number one is also equivalent to the repeating decimal

			(2)
			(3)