A079191 Number of isomorphism classes of anti-commutative closed binary operations on a set of order n, listed by class size.

1, 4, 2, 2, 8, 34, 952, 2, 1, 14, 6, 211, 283, 13570, 31843561

Offset

1,2

Comments

A079188(n)+A079191(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; 4,2; 2,8,34,952; 2,1,14,6,211,283,13570,31843561

A079189(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 A079190(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. A079188, A079189, A079190.

Sequence in context: A020777 A153810 A098134 * A079184 A095800 A055630

Adjacent sequences: A079188 A079189 A079190 * A079192 A079193 A079194

Keyword

nonn,tabf

Author

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

Status

approved