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Finding a non-square mod p

1 · John Cook · Feb. 14, 2026, 10:09 p.m.
Computing Math Number theory mathematics algorithms Number theory Prime numbers
Summary
This blog post discusses the algorithm by Stan Wagon for expressing an odd prime p as a sum of two squares and the prerequisite of finding a non-square mod p, which is a number c that is not congruent to the square of any integer mod p.
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