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Number of isomorphism classes of non-associative non-commutative non-anti-associative anti-commutative closed binary operations on a set of order n, listed by class size.
9

%I #6 Jul 10 2011 18:42:31

%S 0,0,2,0,6,34,952,0,1,12,6,181,283,13333,31839187

%N Number of isomorphism classes of non-associative non-commutative non-anti-associative anti-commutative closed binary operations on a set of order n, listed by class size.

%C A079202(n)+A079203(n)+A079204(n)+A079205(n)+A079197(n)+A079207(n)+A079208(n)+A079209(n)+A063524(n)=A079171(n)

%C Elements per row: 1,2,4,8,16,30,... (given by A027423, number of positive divisors of n!)

%C First four rows: 0; 0,2; 0,6,34,952; 0,1,12,6,181,283,13333,31839187

%C A079232(x) is equal to the sum of the products of each element in row x of this sequence and the corresponding element of A079210.

%C The sum of each row x of this sequence is given by A079233(x).

%H C. van den Bosch, <a href="http://cosmos.ucc.ie/~cjvdb1/html/binops.shtml">Closed binary operations on small sets</a>

%H <a href="/index/Gre#groupoids">Index entries for sequences related to groupoids</a>

%Y Cf. A079202, A079204, A079205, A079197, A079207, A079208, A079209, A079232, A079233.

%K nonn,tabf

%O 1,3

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