%I #8 Mar 30 2012 17:37:12
%S 0,6,3201,178937984,2483527282664925,14325590003288422852104768,
%T 50976900301814583996024242298024434780,
%U 155682086691137947272042494203068030678979503481450216
%N Number of isomorphism classes of non-commutative closed binary operations (groupoids) on a set of order n.
%C A001425(n)+a(n)=A001329(n).
%C Each a(n) is equal to the sum of the elements in row n of A079184.
%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>
%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_, Dec 12 2003