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A079178 Number of isomorphism classes of non-anti-associative closed binary operations on a set of order n, listed by class size. 6
0, 2, 6, 3, 10, 78, 3229, 2, 1, 12, 30, 246, 495, 48427, 178914959 (list; graph; refs; listen; history; internal format)
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: 0; 2,6; 3,10,78,3229; 2,1,12,30,246,495,48427,178914959

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. A079176, A079177, A079179.

Sequence in context: A167979 A180428 A130684 * A113552 A176352 A064736

Adjacent sequences:  A079175 A079176 A079177 * A079179 A079180 A079181

KEYWORD

nonn,tabf

AUTHOR

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

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Last modified February 17 17:35 EST 2012. Contains 206061 sequences.