Correction to: ``On the finite index subgroups of Houghton's groups'' (Q6077861)

In [Arch. Math. 118, No. 2, 113--121 (2022; Zbl 1497.20037)], the author mistakenly assumes that if \(\mathbb{Z}^{n}=\langle e_{1},\ldots, e_{n} \rangle\), then all finite index subgroups of \(\mathbb{Z}^{n}\) have the form \(\langle c_{1}e_{1}, \dots, c_{n}e_{n}\rangle\) for some constants \(c_{1}, \ldots, c_{n} \in \mathbb{N}\) (a remark from \textit{D. Holt}). This paper is dedicated to correcting that mistake.