%I A058123
%S A058123 1,2,2,5,7,6,19,37,44,26,132,216,351,326,135,3107,1780,3093,4157,2961,
%T A058123 875,623615,32652,33445,53145,56020,30395,6749
%N A058123 Triangle: semigroups of order n with k idempotents, considered to be 
               equivalent when they are isomorphic or anti-isomorphic (by reversal 
               of the operator).
%H A058123 <a href="Sindx_Se.html#semigroups">Index entries for sequences related 
               to semigroups</a>
%e A058123 1; 2,2; 5,7,6; 19,37,44,26; 132,216,351,326,135; ...
%Y A058123 Row sums give A001423. Main diagonal: A002788. Columns 1-3: A002787, 
               A002788, A005591.
%Y A058123 Sequence in context: A136536 A023507 A095674 this_sequence A035586 A097050 
               A095295
%Y A058123 Adjacent sequences: A058120 A058121 A058122 this_sequence A058124 A058125 
               A058126
%K A058123 nonn,tabl,hard
%O A058123 1,2
%A A058123 Christian G. Bower (bowerc(AT)usa.net), Nov 10 2000