2-bit Walsh permutation
There are A002884(2) = 2 * 3 = 6 invertible binary 2×2 matrices.
They form the general linear group GL(3,2). It is isomorphic to the symmetric group S3 and the dihedral group D3 (see here).
| overview | transformation arrows | transformed object | |||
|---|---|---|---|---|---|
| + | − | + | − | + | − |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
| transformed objects in two directions | ||||
|---|---|---|---|---|
| vector | det. | arrows | as inverse | binary |
| 1 2 | + |
|
| |
| 2 1 | − |
|
| |
| 1 3 | + |
|
|
|
| 3 1 | − |
|
|
|
| 3 2 | + |
|
|
|
| 2 3 | − |
|
|
|
Cayley table
![]() |
![]() |
![]() (same as 4×4 matrices without trivial fixed point) |
![]() |






















.svg.png)

.svg.png)
%253B_subgroup_of_S4_(elements_0%252C2%252C6%252C8%252C12%252C14).svg.png)