| 1 | a | b | a2 | ab | ba | b2 | a2b | aba | ab2 | ba2 | b2a | a2ba | a2b2 | aba2 | ab2a | b2a2 | a2ba2 | a2b2a | ab2a2 | a2b2a2 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1 | 1 | a | b | a2 | ab | ba | b2 | a2b | aba | ab2 | ba2 | b2a | a2ba | a2b2 | aba2 | ab2a | b2a2 | a2ba2 | a2b2a | ab2a2 | a2b2a2 |
| a | a | a2 | ab | 1 | a2b | aba | ab2 | b | a2ba | a2b2 | aba2 | ab2a | ba | b2 | a2ba2 | a2b2a | ab2a2 | ba2 | b2a | a2b2a2 | b2a2 |
| b | b | ba | b2 | ba2 | ab2 | b2a | b | a2b2 | ab2a | ab | b2a2 | ba | a2b2a | a2b | ab2a2 | aba | ba2 | a2b2a2 | a2ba | aba2 | a2ba2 |
| a2 | a2 | 1 | a2b | a | b | a2ba | a2b2 | ab | ba | b2 | a2ba2 | a2b2a | aba | ab2 | ba2 | b2a | a2b2a2 | aba2 | ab2a | b2a2 | ab2a2 |
| ab | ab | aba | ab2 | aba2 | a2b2 | ab2a | ab | b2 | a2b2a | a2b | ab2a2 | aba | b2a | b | a2b2a2 | a2ba | aba2 | b2a2 | ba | a2ba2 | ba2 |
| ba | ba | ba2 | ab2 | b | a2b2 | ab2a | ab | b2 | a2b2a | a2b | ab2a2 | aba | b2a | b | a2b2a2 | a2ba | aba2 | b2a2 | ba | a2ba2 | ba2 |
| b2 | b2 | b2a | b | b2a2 | ab | ba | b2 | a2b | aba | ab2 | ba2 | b2a | a2ba | a2b2 | aba2 | ab2a | b2a2 | a2ba2 | a2b2a | ab2a2 | a2b2a2 |
| a2b | a2b | a2ba | a2b2 | a2ba2 | b2 | a2b2a | a2b | ab2 | b2a | b | a2b2a2 | a2ba | ab2a | ab | b2a2 | ba | a2ba2 | ab2a2 | aba | ba2 | aba2 |
| aba | aba | aba2 | a2b2 | ab | b2 | a2b2a | a2b | ab2 | b2a | b | a2b2a2 | a2ba | ab2a | ab | b2a2 | ba | a2ba2 | ab2a2 | aba | ba2 | aba2 |
| ab2 | ab2 | ab2a | ab | ab2a2 | a2b | aba | ab2 | b | a2ba | a2b2 | aba2 | ab2a | ba | b2 | a2ba2 | a2b2a | ab2a2 | ba2 | b2a | a2b2a2 | b2a2 |
| ba2 | ba2 | b | a2b2 | ba | b2 | a2b2a | a2b | ab2 | b2a | b | a2b2a2 | a2ba | ab2a | ab | b2a2 | ba | a2ba2 | ab2a2 | aba | ba2 | aba2 |
| b2a | b2a | b2a2 | ab | b2 | a2b | aba | ab2 | b | a2ba | a2b2 | aba2 | ab2a | ba | b2 | a2ba2 | a2b2a | ab2a2 | ba2 | b2a | a2b2a2 | b2a2 |
| a2ba | a2ba | a2ba2 | b2 | a2b | ab2 | b2a | b | a2b2 | ab2a | ab | b2a2 | ba | a2b2a | a2b | ab2a2 | aba | ba2 | a2b2a2 | a2ba | aba2 | a2ba2 |
| a2b2 | a2b2 | a2b2a | a2b | a2b2a2 | b | a2ba | a2b2 | ab | ba | b2 | a2ba2 | a2b2a | aba | ab2 | ba2 | b2a | a2b2a2 | aba2 | ab2a | b2a2 | ab2a2 |
| aba2 | aba2 | ab | b2 | aba | ab2 | b2a | b | a2b2 | ab2a | ab | b2a2 | ba | a2b2a | a2b | ab2a2 | aba | ba2 | a2b2a2 | a2ba | aba2 | a2ba2 |
| ab2a | ab2a | ab2a2 | a2b | ab2 | b | a2ba | a2b2 | ab | ba | b2 | a2ba2 | a2b2a | aba | ab2 | ba2 | b2a | a2b2a2 | aba2 | ab2a | b2a2 | ab2a2 |
| b2a2 | b2a2 | b2 | a2b | b2a | b | a2ba | a2b2 | ab | ba | b2 | a2ba2 | a2b2a | aba | ab2 | ba2 | b2a | a2b2a2 | aba2 | ab2a | b2a2 | ab2a2 |
| a2ba2 | a2ba2 | a2b | ab2 | a2ba | a2b2 | ab2a | ab | b2 | a2b2a | a2b | ab2a2 | aba | b2a | b | a2b2a2 | a2ba | aba2 | b2a2 | ba | a2ba2 | ba2 |
| a2b2a | a2b2a | a2b2a2 | b | a2b2 | ab | ba | b2 | a2b | aba | ab2 | ba2 | b2a | a2ba | a2b2 | aba2 | ab2a | b2a2 | a2ba2 | a2b2a | ab2a2 | a2b2a2 |
| ab2a2 | ab2a2 | ab2 | b | ab2a | ab | ba | b2 | a2b | aba | ab2 | ba2 | b2a | a2ba | a2b2 | aba2 | ab2a | b2a2 | a2ba2 | a2b2a | ab2a2 | a2b2a2 |
| a2b2a2 | a2b2a2 | a2b2 | ab | a2b2a | a2b | aba | ab2 | b | a2ba | a2b2 | aba2 | ab2a | ba | b2 | a2ba2 | a2b2a | ab2a2 | ba2 | b2a | a2b2a2 | b2a2 |
| Length: | Presentation: | Description: | Related: |
|---|---|---|---|
| 8 | 〈a, b | aaa=ab, bbb=1〉 | Finite non-commutative monoid with 21 elements | 6 isomorphic, 9 anti-isomorphic |
| 8 | 〈a, b | aaa=1, abbb=b〉 | Finite non-commutative monoid with 21 elements | 10 isomorphic, 5 anti-isomorphic |
| 9 | 〈a, b | aaa=ab, bbb=b〉 | Finite non-commutative monoid with 21 elements | 1 anti-isomorphic |
| 10 | 〈a, b | aaa=aa, bbb=ab〉 | Finite non-commutative monoid with 21 elements | |
| 10 | 〈a, b | aaa=a, abbbb=b〉 | Finite non-commutative monoid with 21 elements | |
| 11 | 〈a, b | aaaaa=b, abbbb=1〉 | Isomorphic to ℤ21 | 13 isomorphic |
| 11 | 〈a, b | bab=aaa, abba=b〉 | Finite non-commutative monoid with 21 elements | |
| 11 | 〈a, b | bab=aaa, bbb=aa〉 | Finite non-commutative monoid with 21 elements | |
| 11 | 〈a, b | aab=ba, ababab=1〉 | Finite non-Abelian group with 21 elements | 1 isomorphic |
| 11 | 〈a, b | aaa=a, ababbb=b〉 | Finite non-commutative monoid with 21 elements | 1 isomorphic |
| 11 | 〈a, b | aba=b, baaaab=a〉 | Finite non-commutative monoid with 21 elements | |
| 11 | 〈a, b | aaa=1, abbab=aba〉 | Finite non-commutative monoid with 21 elements |
| Length: | Presentation: |
|---|---|
| 10 | 〈a, b | aaa=1, aababb=b〉 |
| 10 | 〈a, b | aaa=1, abaabb=b〉 |
| 10 | 〈a, b | aaa=1, ababab=b〉 |
| 11 | 〈a, b | aaa=1, ababb=aab〉 |
| 11 | 〈a, b | aaa=1, baabb=aab〉 |
| 11 | 〈a, b | aaa=1, babab=aab〉 |