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A079208 Number of isomorphism classes of associative non-commutative non-anti-associative anti-commutative closed binary operations on a set of order n, listed by class size. 9
0, 2, 0, 2, 0, 0, 0, 2, 0, 0, 0, 1, 0, 0, 0 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

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; 2,0; 2,0,0,0; 2,0,0,0,1,0,0,0

A079242(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 A079243(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 semigroups

CROSSREFS

Cf. A079202, A079203, A079204, A079205, A079197, A079207, A079209, A079242, A079243.

Sequence in context: A193526 A160498 A089800 * A262682 A318983 A318982

Adjacent sequences:  A079205 A079206 A079207 * A079209 A079210 A079211

KEYWORD

nonn,tabf

AUTHOR

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

STATUS

approved

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Last modified October 18 13:43 EDT 2018. Contains 316321 sequences. (Running on oeis4.)