DIOPHANTINE QUADRUPLES AND QUINTUPLES MODULO 4
Andrej Dujella1998
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Abstract
A Diophantine m-tuple with the property D(n) is a set {a 1 , a 2 , . . . a m } of positive integers such that for 1 ≤ i < j ≤ m, the number a i a j + n is a perfect square. In the present paper we give necessary conditions that the elements a i of a set {a 1 , a 2 , a 3 , a 4 , a 5 } must satisfy modulo 4 in order to be a Diophantine quintuple.
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