IMO Shortlist 1969 problem 63
Dodao/la:
arhiva2. travnja 2012. ![(SWE 6)](/media/m/d/0/4/d04d6ca140a33ab00848df66c7164420.png)
Prove that there are infinitely many positive integers that cannot be expressed as the sum of squares of three positive integers.
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$(SWE 6)$ Prove that there are infinitely many positive integers that cannot be expressed as the sum of squares of three positive integers.
Izvor: Međunarodna matematička olimpijada, shortlist 1969