# Pages that link to "Congruence condition for two to be a quadratic residue"

The following pages link to **Congruence condition for two to be a quadratic residue**:

- Every integer that is not a perfect square is a quadratic nonresidue for infinitely many primes (← links)
- Prime divisor of Fermat number is congruent to one modulo large power of two (← links)
- Safe prime has plus or minus two as a primitive root (← links)
- Dirichlet's theorem for modulus eight (← links)
- Dirichlet's theorem for modulus four (← links)
- Product of successive primes in Cunningham chain of the second kind satisfying congruence conditions is Poulet number (← links)
- Euler's criterion (← links)