Even Permutation Groups which are Normal Subgroups of the Permutation Group of Order . They are Finite analogs of the families of simple Lie Groups. The lowest order alternating group is 60. Alternating groups with are non-Abelian Simple Groups. The number of conjugacy classes in the alternating groups for , 3, ... are 1, 3, 4, 5, 7, 9, ... (Sloane's A000702).
See also 15 Puzzle, Finite Group, Group, Lie Group, Simple Group, Symmetric Group
References
Sloane, N. J. A. Sequence
A000702/M2307
in ``An On-Line Version of the Encyclopedia of Integer Sequences.''
http://www.research.att.com/~njas/sequences/eisonline.html and Sloane, N. J. A. and Plouffe, S.
The Encyclopedia of Integer Sequences. San Diego: Academic Press, 1995.
Wilson, R. A. ``ATLAS of Finite Group Representation.''
http://for.mat.bham.ac.uk/atlas/html/contents.html#alt.