## Conway Groups

The Automorphism Group of the Leech Lattice modulo a center of order two is called the'' Conway group. There are 15 exceptional Conjugacy Classes of the Conway group. This group, combined with the Groups and obtained similarly from the Leech Lattice by stabilization of the 1-D and 2-D sublattices, are collectively called Conway groups. The Conway groups are Sporadic Groups.

Wilson, R. A. ATLAS of Finite Group Representation.'' http://for.mat.bham.ac.uk/atlas/html/contents.html#spo.