A079181 Number of isomorphism classes of anti-associative closed binary operations on a set of order n, listed by class size.

1, 2, 0, 0, 2, 0, 8, 0, 0, 2, 0, 29, 0, 383, 17366

Offset

1,2

Comments

A079178(n)+A079181(n)=A079171(n).

Elements per row: 1,2,4,8,16,30,... (given by A027423, number of positive divisors of n!)

First four rows: 1; 2,0; 0,2,0,8; 0,0,2,0,29,0,383,17366

A079179(x) is equal to the sum of the products of each element in row x of this sequence and the corresponding element of A079210.

The sum of each row x of this sequence is given by A079180(x).

Links

Table of n, a(n) for n=1..15.

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

Index entries for sequences related to groupoids

Crossrefs

Cf. A079176, A079177.

Sequence in context: A028959 A317642 A258762 * A093693 A224447 A025436

Adjacent sequences: A079178 A079179 A079180 * A079182 A079183 A079184

Keyword

nonn,tabf

Author

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

Status

approved