A079180 Number of isomorphism classes of anti-associative closed binary operations on a set of order n.

1, 0, 2, 10, 17780

Offset: 0

Author

Christian van den Bosch (cjb(AT)cjb.ie), Jan 03 2003

Keywords

• nonn

Links

• Christian van den Bosch, Closed binary operations on small sets
• Index entries for sequences related to semigroups
• Index entries for sequences related to groupoids

Crossrefs

Row sums of A079181.

Cf. A001329, A079177, A079179 (labeled case).

Formula

a(n) = A001329(n) - A079177(n).

Extensions

a(0)=1 prepended and a(1) corrected by Kamil Zabielski, Aug 28 2024