If there is an integer such that
then is said to be a biquadratic residue (mod ). If not, is said to be a biquadratic nonresidue (mod ).
If there is an integer such that
then is said to be a biquadratic residue (mod ). If not, is said to be a biquadratic nonresidue (mod ).
Weisstein, Eric W. "Biquadratic Residue." From MathWorld--A Wolfram Web Resource. https://mathworld.wolfram.com/BiquadraticResidue.html