A079173 Number of isomorphism classes of non-associative closed binary operations on a set of order n.

0, 5, 3306, 178981764, 2483527537092910, 14325590003318891522247046, 50976900301814584087291487087212542367, 155682086691137947272042502251643461917498831796991599, 541851439802559836957713164869818405872834954135521300809796661279574643

Offset: 1

Author

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

Keywords

• nonn

Comments

Each a(n) is equal to the sum of the elements in row n of A079174.

Links

• Christian van den Bosch, Closed binary operations on small sets. [Wayback Machine link]
• Index entries for sequences related to groupoids.

Crossrefs

Cf. A001329, A027851, A079172, A079174.

Formula

a(n) = A001329(n) - A027851(n).

Extensions

More terms from Christian G. Bower, Nov 26 2003

a(8)-a(9) added using the data at A001329 and A027851 by Amiram Eldar, Jul 19 2025