This page gives information on groups of orders 12, 24 and 48 which "contain" A4, as a normal subgroup, as a quotient group, or as a combination of these.
The information is currently not quite complete. The green table cell indicates missing information, some of the other information may be wrong.
The image to the left shows how how some of the groups listed above are related (direct products are omitted from this diagram). The names of the groups, as given above, are shown in black. Green lines join groups to their normal subgroups. Red lines join groups to their quotient groups. The blue above each group shows it broken down into components; the light blue arcs indicate what the central extensions by C2 act on.
We can expand the diagram above to include all the groups listed in the table. The resulting diagram is below. The meanings of the colours of the lines is:
red | enlarge the group by adding a centre |
dashed red | enlarge the group by adding two "centres", such that neither is central |
green | enlarge the group by building a semidirect product of it |
blue | enlarge the group by forming a direct product |
pink | enlarge the group using it to build a semidirect product of something else |
Orange triangles and up-arrows ↑ are used on this page to indicate central extensions.
The letters used for the permutations relate to the grids used used in the page GL(2,3), with the letters in these positions.
More miscellaneous short pages on finite groups
More pages on groups
Copyright N.S.Wedd 2008,2009