%I A029851
%S A029851 1,1,3,12,64,405,3312,44370
%N A029851 Number of self-converse semigroups.
%H A029851 Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/
               Semigroup.html">Link to a section of The World of Mathematics.</a>
%H A029851 <a href="Sindx_Se.html#semigroups">Index entries for sequences related 
               to semigroups</a>
%Y A029851 a(n)=A001423(n)*2-A027851(n). Cf. A001426.
%Y A029851 Sequence in context: A135889 A124562 A052757 this_sequence A111262 A139134 
               A109577
%Y A029851 Adjacent sequences: A029848 A029849 A029850 this_sequence A029852 A029853 
               A029854
%K A029851 nonn,hard,nice
%O A029851 0,3
%A A029851 Christian G. Bower (bowerc(AT)usa.net), Jan 27 1998. Updated Feb 19 2001