A079196 Number of isomorphism classes of non-associative commutative closed binary operations on a set of order n.

0, 0, 1, 117, 43910, 254429575, 30468670168769, 91267244789189717968, 8048575431238519331999349995, 24051927835861852500932966021639447717, 2755731922430783367615449408031031255128360423993

Offset: 0

Author

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

Keywords

• nonn

Links

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

Crossrefs

Row sums of A079197.

Cf. A001329, A001425, A001426, A079193, A079195 (labeled case), A079199.

Formula

A079193(n) + a(n) + A079199(n) + A001426(n) = A001329(n).

a(n) = A001425(n) - A001426(n). - Andrew Howroyd, Jan 26 2022

Extensions

a(0)=0 prepended and a(5)-a(10) added by Andrew Howroyd, Jan 26 2022