properties of the index of an integer with respect to a primitive root
Definition.
Let be an integer such that the integer is a primitive root for . Suppose is another integer relatively prime to . The index of (to base ) is the smallest positive integer such that , and it is denoted by or .
Proposition.
Suppose is a primitive root of .
- 1.
; , where is the Euler phi function.
- 2.
if and only if .
- 3.
.
- 4.
for any .