ATLAS: Dempwolff group 25.L5(2) (non­split extension)

Order = 319979520 =
Mult = 1.
Out = 1.
The page for the image L5(2) is available here.

The following information is available for 25.L5(2):

Standard generators

Standard generators of the Dempwolff group 25.L5(2) are a and b where a has order 2, b has order 5, ab has order 21, ababb has order 10, abababbbb has order 28 and abababbbabb has order 5. These generators map onto standard generators of L5(2).
NB: There is just one class of involutions of 25.L5(2) not in the normal 25 and it maps onto class 2A of L5(2).


A presentation of 25.L5(2) on its standard generators is given below.

< a, b | a2 = b5 = (ab)21 = [a, b2]4 = [a, b-2ab-2][a, b]3 = (ababab-2)2(abab-1ab)2(ab-1)2 = 1 >.

This presentation is available in Magma format as follows: 25L5(2) on a and b.


The representations of 25.L5(2) available are:
Main ATLAS page Go to main ATLAS (version 2.0) page.
Miscellaneous groups page Go to miscellaneous groups page.
Old 25L5(2) page Go to old 25L5(2) page (on the L5(2) page) - ATLAS version 1.
ftp access Anonymous ftp access is also available on

Version 2.0 created on 5th May 1999.
Last updated 27.05.99 by JNB.
Information checked to Level 1 on 27.05.99 by JNB.
R.A.Wilson, R.A.Parker and J.N.Bray.