Power Residue
Power Residue
If the congruence xn = a (mod m) has a solution, then a is called a power residue of m of the nth order. Here, n is an integer greater than 1, and m is an integer. When n = 2, a is said to be a quadratic residue of m; when n = 3, a is a cubic residue of m; and when n = 4, a is a biquadratic residue of m.