Find all integers , , such that the numbers , , , give distinct remainders when divided by .
Solution
We claim that those integers are and .
Suppose is a composite integer, , . If , then divides and . Since , it follows that and yield equal remainders (both ) at division by . If then and are divisible by . Since , it follows that does not satisfy the desired property.
It remains to settle the case of prime . The value checks; let then . From Wilson's theorem we have
and then
Since yields remainder at division by , it follows , that is , which checks.
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