%I A133983
%S A133983 1,2,3,8,15,50,119,493
%N A133983 Number of nonisomorphic n-element self-dual posets.
%Y A133983 Sequence in context: A006882 A080498 A148013 this_sequence A005162 A129108 
               A153699
%Y A133983 Adjacent sequences: A133980 A133981 A133982 this_sequence A133984 A133985 
               A133986
%K A133983 nonn
%O A133983 1,2
%A A133983 R. P. Stanley (rstan(AT)math.mit.edu), Jan 08 2008