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

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

Offset

1,2

Comments

A027851(n)+A079173(n)=A001329(n)

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

Links

Table of n, a(n) for n=1..7.

C. van den Bosch, Closed binary operations on small sets

Index entries for sequences related to groupoids

Crossrefs

Cf. A027851, A079172, A079174.

Sequence in context: A137841 A204940 A172954 * A073826 A159397 A024074

Adjacent sequences: A079170 A079171 A079172 * A079174 A079175 A079176

Keyword

nonn

Author

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

Extensions

More terms from Christian G. Bower, Nov 26 2003

Status

approved