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Number of non-anti-associative closed binary operations on a set of order n.
8

%I #10 Sep 03 2024 04:27:02

%S 1,14,19631,4294545736

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

%C Each a(n) is equal to the sum of the products of each element in row n of A079178 and the corresponding element of A079210.

%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>

%F a(n) = A002489(n) - A079179(n).

%Y Cf. A079177, A079178, A079179.

%K nonn

%O 1,2

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