Number of n-element groupoids with an identity, considered to be equivalent when they are isomorphic or anti-isomorphic (by reversal of the operator).
A090600
Number of n-element groupoids with an identity, considered to be equivalent when they are isomorphic or anti-isomorphic (by reversal of the operator).
Terms
- a(0) =1a(1) =2a(2) =30a(3) =22456a(4) =3179460875
External references
- oeis: A090600