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A079191 Number of isomorphism classes of anti-commutative closed binary operations on a set of order n, listed by class size. +0
4
1, 4, 2, 2, 8, 34, 952, 2, 1, 14, 6, 211, 283, 13570, 31843561 (list; graph; listen)
OFFSET

1,2

COMMENT

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

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 this_sequence A079184 A095800 A055630

Adjacent sequences: A079188 A079189 A079190 this_sequence A079192 A079193 A079194

KEYWORD

nonn,tabf

AUTHOR

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

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Last modified December 8 08:31 EST 2009. Contains 170430 sequences.


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