| 1 | a | b | a2 | ab | ba | a3 | a2b | aba | ba2 | a3b | a2ba | aba2 | ba3 | a3ba | a2ba2 | aba3 | a3ba2 | a2ba3 | a3ba3 | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1 | 1 | a | b | a2 | ab | ba | a3 | a2b | aba | ba2 | a3b | a2ba | aba2 | ba3 | a3ba | a2ba2 | aba3 | a3ba2 | a2ba3 | a3ba3 |
| a | a | a2 | ab | a3 | a2b | aba | 1 | a3b | a2ba | aba2 | b | a3ba | a2ba2 | aba3 | ba | a3ba2 | a2ba3 | ba2 | a3ba3 | ba3 |
| b | b | ba | b | ba2 | ab | ba | ba3 | a2b | aba | ba2 | a3b | a2ba | aba2 | ba3 | a3ba | a2ba2 | aba3 | a3ba2 | a2ba3 | a3ba3 |
| a2 | a2 | a3 | a2b | 1 | a3b | a2ba | a | b | a3ba | a2ba2 | ab | ba | a3ba2 | a2ba3 | aba | ba2 | a3ba3 | aba2 | ba3 | aba3 |
| ab | ab | aba | ab | aba2 | a2b | aba | aba3 | a3b | a2ba | aba2 | b | a3ba | a2ba2 | aba3 | ba | a3ba2 | a2ba3 | ba2 | a3ba3 | ba3 |
| ba | ba | ba2 | ab | ba3 | a2b | aba | b | a3b | a2ba | aba2 | b | a3ba | a2ba2 | aba3 | ba | a3ba2 | a2ba3 | ba2 | a3ba3 | ba3 |
| a3 | a3 | 1 | a3b | a | b | a3ba | a2 | ab | ba | a3ba2 | a2b | aba | ba2 | a3ba3 | a2ba | aba2 | ba3 | a2ba2 | aba3 | a2ba3 |
| a2b | a2b | a2ba | a2b | a2ba2 | a3b | a2ba | a2ba3 | b | a3ba | a2ba2 | ab | ba | a3ba2 | a2ba3 | aba | ba2 | a3ba3 | aba2 | ba3 | aba3 |
| aba | aba | aba2 | a2b | aba3 | a3b | a2ba | ab | b | a3ba | a2ba2 | ab | ba | a3ba2 | a2ba3 | aba | ba2 | a3ba3 | aba2 | ba3 | aba3 |
| ba2 | ba2 | ba3 | a2b | b | a3b | a2ba | ba | b | a3ba | a2ba2 | ab | ba | a3ba2 | a2ba3 | aba | ba2 | a3ba3 | aba2 | ba3 | aba3 |
| a3b | a3b | a3ba | a3b | a3ba2 | b | a3ba | a3ba3 | ab | ba | a3ba2 | a2b | aba | ba2 | a3ba3 | a2ba | aba2 | ba3 | a2ba2 | aba3 | a2ba3 |
| a2ba | a2ba | a2ba2 | a3b | a2ba3 | b | a3ba | a2b | ab | ba | a3ba2 | a2b | aba | ba2 | a3ba3 | a2ba | aba2 | ba3 | a2ba2 | aba3 | a2ba3 |
| aba2 | aba2 | aba3 | a3b | ab | b | a3ba | aba | ab | ba | a3ba2 | a2b | aba | ba2 | a3ba3 | a2ba | aba2 | ba3 | a2ba2 | aba3 | a2ba3 |
| ba3 | ba3 | b | a3b | ba | b | a3ba | ba2 | ab | ba | a3ba2 | a2b | aba | ba2 | a3ba3 | a2ba | aba2 | ba3 | a2ba2 | aba3 | a2ba3 |
| a3ba | a3ba | a3ba2 | b | a3ba3 | ab | ba | a3b | a2b | aba | ba2 | a3b | a2ba | aba2 | ba3 | a3ba | a2ba2 | aba3 | a3ba2 | a2ba3 | a3ba3 |
| a2ba2 | a2ba2 | a2ba3 | b | a2b | ab | ba | a2ba | a2b | aba | ba2 | a3b | a2ba | aba2 | ba3 | a3ba | a2ba2 | aba3 | a3ba2 | a2ba3 | a3ba3 |
| aba3 | aba3 | ab | b | aba | ab | ba | aba2 | a2b | aba | ba2 | a3b | a2ba | aba2 | ba3 | a3ba | a2ba2 | aba3 | a3ba2 | a2ba3 | a3ba3 |
| a3ba2 | a3ba2 | a3ba3 | ab | a3b | a2b | aba | a3ba | a3b | a2ba | aba2 | b | a3ba | a2ba2 | aba3 | ba | a3ba2 | a2ba3 | ba2 | a3ba3 | ba3 |
| a2ba3 | a2ba3 | a2b | ab | a2ba | a2b | aba | a2ba2 | a3b | a2ba | aba2 | b | a3ba | a2ba2 | aba3 | ba | a3ba2 | a2ba3 | ba2 | a3ba3 | ba3 |
| a3ba3 | a3ba3 | a3b | a2b | a3ba | a3b | a2ba | a3ba2 | b | a3ba | a2ba2 | ab | ba | a3ba2 | a2ba3 | aba | ba2 | a3ba3 | aba2 | ba3 | aba3 |
| Length: | Presentation: | Description: | Related: |
|---|---|---|---|
| 8 | 〈a, b | aab=a, bbbb=1〉 | Finite non-commutative monoid with 20 elements | 3 isomorphic, 1 anti-isomorphic |
| 8 | 〈a, b | ab=aa, bbbb=1〉 | Finite non-commutative monoid with 20 elements | 1 isomorphic |
| 9 | 〈a, b | abab=a, bbbb=1〉 | Finite non-commutative monoid with 20 elements | 2 isomorphic |
| 9 | 〈a, b | aba=ab, bbbb=1〉 | Finite non-commutative monoid with 20 elements | 1 isomorphic, 1 anti-isomorphic |
| 9 | 〈a, b | ab=aa, bbbb=b〉 | Finite non-commutative monoid with 20 elements | |
| 10 | 〈a, b | abb=aab, aaaa=1〉 | Finite non-commutative monoid with 20 elements | 2 isomorphic |
| 10 | 〈a, b | baa=abb, abab=1〉 | Finite non-Abelian group with 20 elements | 1 isomorphic, 1 anti-isomorphic |
| 10 | 〈a, b | aaaaa=1, abbbb=1〉 | Isomorphic to ℤ20 | 16 isomorphic |
| 10 | 〈a, b | aab=bb, aaaa=a〉 | Finite non-commutative monoid with 20 elements | |
| 10 | 〈a, b | aaa=bb, bab=aa〉 | Finite non-commutative monoid with 20 elements | 1 isomorphic |
| 10 | 〈a, b | aba=a, aaaa=bb〉 | Finite non-commutative monoid with 20 elements | |
| 10 | 〈a, b | aba=b, aaaa=bb〉 | Finite non-commutative monoid with 20 elements | |
| 10 | 〈a, b | ab=aa, bbbb=bb〉 | Finite non-commutative monoid with 20 elements | |
| 11 | 〈a, b | aaaa=aa, abbb=b〉 | Finite non-commutative monoid with 20 elements | |
| 11 | 〈a, b | aaab=bb, bbba=a〉 | Finite non-commutative monoid with 20 elements | |
| 11 | 〈a, b | aaaa=a, bbbbb=a〉 | Finite commutative monoid with 20 elements | |
| 11 | 〈a, b | aaaa=b, bbbbb=a〉 | Finite commutative monoid with 20 elements | |
| 11 | 〈a, b | aaaa=b, bbbbb=b〉 | Finite commutative monoid with 20 elements | |
| 11 | 〈a, b | aab=ba, abbabb=1〉 | Finite non-Abelian group with 20 elements | 2 isomorphic |
| 11 | 〈a, b | aba=bb, baaab=a〉 | Finite non-commutative monoid with 20 elements | |
| 11 | 〈a, b | aab=aa, baba=bb〉 | Finite non-commutative monoid with 20 elements | |
| 11 | 〈a, b | aba=aa, aaaa=bb〉 | Finite non-commutative monoid with 20 elements | |
| 11 | 〈a, b | aba=aa, aaab=bb〉 | Finite non-commutative monoid with 20 elements | |
| 11 | 〈a, b | aba=bb, abb=aaa〉 | Finite non-commutative monoid with 20 elements | |
| 11 | 〈a, b | aaaa=1, aabab=ab〉 | Finite non-commutative monoid with 20 elements | 1 isomorphic |
| 11 | 〈a, b | aba=b, aaaaabb=1〉 | Finite non-Abelian group with 20 elements | 3 isomorphic |
| 11 | 〈a, b | aab=a, bbbbb=bb〉 | Finite non-commutative monoid with 20 elements | |
| 11 | 〈a, b | ab=aa, bbbb=bbb〉 | Finite non-commutative monoid with 20 elements |
| Length: | Presentation: |
|---|---|
| 11 | 〈a, b | aaaa=1, abaaab=b〉 |