Semigroups of order n with 1 idempotent, considered to be equivalent when they are isomorphic or anti-isomorphic (by reversal of the operator).
A002786
Semigroups of order n with 1 idempotent, considered to be equivalent when they are isomorphic or anti-isomorphic (by reversal of the operator).
Terms
- a(0) =1a(1) =2a(2) =5a(3) =19a(4) =132a(5) =3107a(6) =623615a(7) =1834861133
External references
- oeis: A002786