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Number of isomorphism classes of non-associative non-commutative closed binary operations on a set of order n.
9

%I #7 Mar 30 2012 17:37:12

%S 0,4,3189,178937854,2483527282663335,14325590003288422852078277,

%T 50976900301814584087291456618542388746

%N Number of isomorphism classes of non-associative non-commutative closed binary operations on a set of order n.

%C A079193(n)+A079196(n)+A079199(n)+A001426(n)=A001329(n).

%C Each a(n) is equal to the sum of the elements in row n of A079194.

%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. A079192, A079194, A079196, A079199, A001426.

%Y a(n) = A001329(n)-A001425(n)-A027851(n)+A001426(n).

%Y a(n)+A079196(n)+A079199(n)+A001426(n)=A001329(n).

%K nonn

%O 1,2

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

%E Edited and extended by _Christian G. Bower_, Nov 26 2003