[seqfan] Re: Maximal number of touching points between unit spheres

[Richard J. Mathar]

In answer to http://list.seqfan.eu/pipermail/seqfan/2018-March/018447.html

> The five points representing the vertices of a pair of tetrahedrons joined
> at one face:
> ...
> The distances AB, BC, CA, DA, DB, DC, EA, EB, EC are all 1.

The main problem here is that the tetrahedra are a subset of
points on the h.c.p. lattice (stacking ABABAB...), not the f.c.c. 
lattice which I and A214813 are searching for.

RJM