Search: id:A005591 Results 1-1 of 1 results found. %I A005591 M4246 %S A005591 6,44,351,3093,33445 %N A005591 Number of semigroups of order n with 3 idempotents, considered to be equivalent when they are isomorphic or anti-isomorphic (by reversal of the operator). %D A005591 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence). %D A005591 H. Juergensen and P. Wick, Die Halbgruppen von Ordnungen <= 7, Semigroup Forum, 14 (1977), 69-79. %D A005591 R. J. Plemmons, There are 15973 semigroups of order 6, Math. Algor., 2 (1967), 2-17; 3 (1968), 23. %H A005591 Index entries for sequences related to semigroups %Y A005591 Column 3 of A058123. %Y A005591 Sequence in context: A115969 A082412 A108452 this_sequence A052204 A147688 A090442 %Y A005591 Adjacent sequences: A005588 A005589 A005590 this_sequence A005592 A005593 A005594 %K A005591 nonn %O A005591 3,1 %A A005591 N. J. A. Sloane (njas(AT)research.att.com). Search completed in 0.001 seconds