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A079188 Number of isomorphism classes of non-anti-commutative closed binary operations on a set of order n, listed by class size. 4
0, 0, 4, 1, 4, 44, 2285, 0, 0, 0, 24, 64, 212, 35240, 147088764 (list; graph; refs; listen; history; internal format)
OFFSET

1,3

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: 0; 0,4; 1,4,44,2285; 0,0,0,24,64,212,35240,147088764

A079176(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 A079177(x).

LINKS

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

Index entries for sequences related to groupoids

CROSSREFS

Cf. A079186, A079187, A079191.

Sequence in context: A066808 A033918 A136467 * A076810 A185373 A194127

Adjacent sequences:  A079185 A079186 A079187 * A079189 A079190 A079191

KEYWORD

nonn,tabf

AUTHOR

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

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Last modified February 17 05:54 EST 2012. Contains 205985 sequences.