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Number of non-associative closed binary operations on a set of order n.
4

%I #11 Mar 02 2020 07:35:43

%S 0,8,19570,4294963804,298023223876769393,

%T 10314424798490535546154887938,

%U 256923577521058878088611477224227878265543,6277101735386680763835789423207666416102355296268686994710,196627050475552913618075908526912116283103450944214766927276968172610579252347

%N Number of non-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 A079174 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) - A023814(n).

%Y Cf. A023814, A079173, A079174.

%K nonn

%O 1,2

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

%E More terms from _Christian G. Bower_, Nov 26 2003

%E More terms from _Jinyuan Wang_, Mar 02 2020