Prove for any integer , there exists a polynomial of degree ,
with the following properties.
(1) are all positive integers;
(2) For any positive integer and arbitrary () positive integers that are different from each other, we have
Solution
Let
Obviously, is a monic polynomial of degree with positive integer coefficients. We are going to prove that has property (2).
For any integer , since , we know that there exists definitely a multiple of 4 in any consecutive numbers . Then from , we have .
Then for any () positive integers , we have
On the other hand, for any positive integer , we have
. Therefore,
which implies that . We then find the required and complete the proof.
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