index of an integer with respect to a primitive root
(Definition)
Definition 1Let $m>1$ be an integer such that the integer $g$ is a primitive root for $m$ . Suppose $a$ is another integer relatively prime to $g$ . The index of $a$ (to base$g$ ) is the smallest positive integer $n$ such that $g^n\equiv a \mod m$ , and it is denoted by $\operatorname{ind} a$ or $\operatorname{ind}_g a$ .
If $m$ has a primitive root the index with respect to a primitive root is a very useful tool to solve polynomial congruences modulo $m$ .
"index of an integer with respect to a primitive root" is owned by alozano.
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