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A079207 Number of isomorphism classes of associative non-commutative non-anti-associative non-anti-commutative closed binary operations on a set of order n, listed by class size. 9
0, 0, 0, 0, 0, 4, 6, 0, 0, 0, 4, 4, 0, 46, 73 (list; graph; refs; listen; history; internal format)
OFFSET

1,6

COMMENTS

A079202(n)+A079203(n)+A079204(n)+A079205(n)+A079197(n)+A079207(n)+A079208(n)+A079209(n)+A063524(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; 0,0; 0,0,4,6; 0,0,0,4,4,0,46,73

A079240(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 A079241(x).

LINKS

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

Index entries for sequences related to semigroups

CROSSREFS

Cf. A079202, A079203, A079204, A079205, A079197, A079208, A079209, A079240, A079241.

Sequence in context: A064612 A005927 A201529 * A056945 A070683 A195785

Adjacent sequences:  A079204 A079205 A079206 * A079208 A079209 A079210

KEYWORD

nonn,tabf

AUTHOR

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

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Last modified February 17 14:50 EST 2012. Contains 206050 sequences.