%I A088811
%S A088811 0,0,1,1,4,6,13,19,41,54,110,157,277,394,706,970,1691,2376,3905,5494,
%T A088811 9130,12355,20262,28146,44316,61761,98023,132891
%N A088811 Number of subsets of {1, ..., n} that are sum-free but not double-free.
%C A088811 a(n) = A088808(n) - A088812(n) = A085489(n) - A007865(n).
%H A088811 Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/
               Double-FreeSet.html">Double-Free Set</a>
%H A088811 Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/
               Sum-FreeSet.html">Sum-Free Set</a>
%H A088811 Reinhard Zumkeller, <a href="a088808.txt">Illustration of initial terms</
               a>
%Y A088811 Sequence in context: A010061 A063186 A069061 this_sequence A007977 A013122 
               A012964
%Y A088811 Adjacent sequences: A088808 A088809 A088810 this_sequence A088812 A088813 
               A088814
%K A088811 nonn
%O A088811 0,5
%A A088811 Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), Oct 19 2003