The Mathieu group
is a sporadic group of group
order
.
It is a simple group and a subgroup
of the symmetric group
. Its natural group action
on 12 points is transitive on ordered 5-tuples
of distinct points, with a unique group element
sending any such tuple to any other. It is the automorphism
group of the Steiner system
.
The Schur multiplier and outer automorphism group of both have group order
2. A point stabilizer in its natural group
action is isomorphic to M11.
According to the ATLAS, standard generators
and
may be chosen so that
,
,
, and
have orders 2, 3, 11,
and 6, respectively.
The group is implemented in the Wolfram Language as MathieuGroupM12[].
Pegg (2016) gives an interactive visualization of words in two group
generators for
represented by matrices over a finite
field.