On the extension of $D(-8k^2)$-pair $\{8k^2,8k^2+1\}$

Nikola Adžaga, Alan Filipin

Let $n$ be a nonzero integer. A set of $m$ positive integers is called a $D(n)$-$m$-tuple if the product of any two of its distinct elements increased by $n$ is a perfect square. L…