%I A085489
%S A085489 2,4,7,13,22,37,61,102,162,261,410,646,1001,1553,2370,3645,5515,8303,
%T A085489 12470,18713,27811,41244,60962,89733,131870,192522,281125,408680,593880,
%U A085489 855661,1238592,1779614,2563476,3660084,5255913,7473380,10696444,15137517
%N A085489 a(n) = number of subsets of {1,...,n} containing no solutions to x+y=z 
               with x and y distinct (one version of "sum-free subsets").
%H A085489 Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/
               Sum-FreeSet.html">Sum-Free Set</a> [Strictly speaking this link is 
               not relevant, since it uses a different definition of "sum-free".]
%F A085489 a(n) = 2^n - A088809(n). - Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), 
               Oct 19 2003
%Y A085489 See A007865 for another version.
%Y A085489 Sequence in context: A143823 A119983 A151897 this_sequence A101268 A128768 
               A001036
%Y A085489 Adjacent sequences: A085486 A085487 A085488 this_sequence A085490 A085491 
               A085492
%K A085489 nonn,nice
%O A085489 1,1
%A A085489 Eric Weisstein (eric(AT)weisstein.com), Jul 02, 2003
%E A085489 More terms from Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), 
               Jul 13 2003
%E A085489 Edited by David Wasserman (dwasserm(AT)earthlink.net), Apr 16 2008