The question is mainly about structures with one binary operation. On math.SE I would probably add binary-operations (which does not exists here and is not a top-level tag) and abstract-algebra (which is deprecated on MO).
This is somewhat related to this previous conversation:
I saw this image on Wikipedia:
Since there are five "properties" that we can have (in this context), namely: totality, associativity, identity, invertibility and commutativity, there are $\binom {5}{1}+ \binom{5}{2}+ \binom {5} {3} + \binom {5}{4} + \binom {5}{5}=5+10+10+5+1=31$ possible struc...
I saw this image on Wikipedia:
Since there are five "properties" that we can have (in this context), namely: totality, associativity, identity, invertibility and commutativity, there are $\binom {5}{1}+ \binom{5}{2}+ \binom {5} {3} + \binom {5}{4} + \binom {5}{5}=5+10+10+5+1=31$ possible struc...
