Number of associative binary operations on an n-set; number of labeled semigroups.
A023814
Number of associative binary operations on an n-set; number of labeled semigroups.
Terms
- a(0) =1a(1) =1a(2) =8a(3) =113a(4) =3492a(5) =183732a(6) =17061118a(7) =7743056064
External references
- oeis: A023814