Odredi

takav da je izraz

te njegova apsolutna vrijednost postiže maksimum.
Determine

such that the expression

is an integer and its absolute value is maximized.
[lang=hr]
Odredi $n\in\mathbb{Z} $ takav da je izraz $\frac{18n^2+4}{3n+1}\in\mathbb{Z}$ te njegova apsolutna vrijednost postiže maksimum.
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[lang=en]
Determine $n \in \mathbb{Z}$ such that the expression $\frac{18n^2+4}{3n+1}$ is an integer and its absolute value is maximized.
[/lang]