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

1, 0, 2, 10, 17780

Offset

0,3

Links

Table of n, a(n) for n=0..4.

Christian van den Bosch, Closed binary operations on small sets

Index entries for sequences related to semigroups

Index entries for sequences related to groupoids

Formula

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

Crossrefs

Row sums of A079181.

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

Sequence in context: A155733 A080485 A125149 * A027735 A085698 A057095

Adjacent sequences: A079177 A079178 A079179 * A079181 A079182 A079183

Keyword

nonn

Author

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

Extensions

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

Status

approved