A079183 Number of isomorphism classes of non-commutative closed binary operations (groupoids) on a set of order n.

0, 6, 3201, 178937984, 2483527282664925, 14325590003288422852104768, 50976900301814583996024242298024434780, 155682086691137947272042494203068030678979503481450216

Offset

1,2

Comments

Each a(n) is equal to the sum of the elements in row n of A079184.

Links

Table of n, a(n) for n=1..8.

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

Index entries for sequences related to groupoids

Formula

a(n) = A001329(n) - A001425(n).

Crossrefs

Cf. A001329, A001425, A079184.

Sequence in context: A093884 A265869 A274083 * A373236 A030245 A247965

Adjacent sequences: A079180 A079181 A079182 * A079184 A079185 A079186

Keyword

nonn

Author

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

Extensions

Edited and extended by Christian G. Bower, Dec 12 2003

Status

approved