K. Hulek and M. Lönne,

where obtained with the help of the computer algebra system Magma.

The computations can be done as follows:

- Download the file K3.zip.
- Unzip the downloaded file.
- Run "magma K3.m".

The above code uses an algorithm for computing automorphism groups of hyperbolic lattices by M. H. Mertens [1].

This algorithm has been extended by S. Schönnenbeck to output a presentation of these automorphism groups, following the ideas of [2].

The algorithm and its extension are contained in the file "AutHyp.m" provided by the archive "K3.zip".

[1] M. H. Mertens, *Automorphism Groups of Hyperbolic Lattices*, Journal of Algebra 408 (2014), pp. 147-165, DOI.

[2] O. Braun, R. Coulagon, G. Nebe and S. Schönnenbeck, *Computing in arithmetic groups with Voronoi's algorithm*, Journal of Algebra 435 (2015), pp. 263-285, DOI.