ATLAS: Alternating group A9

Order = 181440 =
Mult = 2.
Out = 2.

Standard generators

Standard generators of A9 are a and b where a is in class 3A, b has order 7 and ab has order 9.
In the natural representation we may take a = (1, 2, 3) and b = (3, 4, 5, 6, 7, 8, 9).
Standard generators of the double cover 2.A9 are preimages A and B where A has order 3, and B has order 7.


The representations of A9 available are The representations of 2.A9 available are The representations of S9 = A9:2 available are

Maximal subgroups

The maximal subgroups of A9 are:

Conjugacy classes

We define class 9A to be the class containing b, and class 15A to be the class containing aababb. This choice is compatible with the ABC.
Main ATLAS page Go to main ATLAS (version 2.0) page.
Alternating groups page Go to alternating groups page.
Old A9 page Go to old A9 page - ATLAS version 1.
ftp access Anonymous ftp access is also available on

Version 2.0 file created on 18th April 2000, from Version 1 file last modified on 18.12.97.
Last updated 15.01.02 by RAW.
Information checked to Level 0 on 18.04.00 by RAW.
R.A.Wilson, R.A.Parker and J.N.Bray.