%I A018196
%S A018196 1,4,8,9,15,32
%N A018196 Possible numbers of complements of topologies on 5 points.
%D A018196 J. I. Brown and S. Watson, The number of complements of a topology on 
               n points is at least 2^n (except for some special cases), Discr. 
               Math., 154 (1996), 27-39.
%Y A018196 Sequence in context: A131195 A020217 A141066 this_sequence A072103 A004756 
               A153034
%Y A018196 Adjacent sequences: A018193 A018194 A018195 this_sequence A018197 A018198 
               A018199
%K A018196 nonn
%O A018196 0,2
%A A018196 N. J. A. Sloane (njas(AT)research.att.com).