Abstract
Let n be a nonzero integer. A set of m distinct positive integers is called a D(n)-m-tuple if the product of any two of them increased by n is a perfect square. Let k be a positive integer. In this paper, we show that if {k 2, k 2+1, c, d} is a D(−k 2)-quadruple with c < d, then c = 1 and d = 4k 2+1. This extends the work of the first author [20] and that of Dujella [4].
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Fujita, Y., Togbé, A. The extension of the D(−k 2)-pair {k 2,k 2 + 1}. Period Math Hung 65, 75–81 (2012). https://doi.org/10.1007/s10998-012-2912-x
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DOI: https://doi.org/10.1007/s10998-012-2912-x