A058170 Triangle: Number of asymmetric semigroups of order n with k idempotents, considered to be equivalent when they are isomorphic or anti-isomorphic (by reversal of the operator).
1, 2, 1, 3, 7, 2, 10, 28, 33, 7, 82, 153, 261, 213, 37, 2511, 1227, 2266, 2989, 1709, 263, 600106, 26033, 24176, 39176, 38346, 16306, 2134
Offset: 1
Examples
1; 2,1; 3,7,2; 10,28,33,7; 82,153,261,213,37; ...
Crossrefs
Row sums give A058107.