%I A088813
%S A088813 1,2,4,7,14,26,43,79,137,246,398,733,1237,2314,3586,6730,11051,21096,
%T A088813 31985,61654,102730,199555,301062,589746,942876,1858881,2793703,5524251
%N A088813 Number of subsets of {1, ..., n} that are double-free or sum-free.
%C A088813 a(n) = 2^n - A088812(n) = A050291(n)+A085489(n)-A007865(n).
%H A088813 Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/
               Double-FreeSet.html">Double-Free Set</a>
%H A088813 Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/
               Sum-FreeSet.html">Sum-Free Set</a>
%Y A088813 Sequence in context: A167606 A065455 A026010 this_sequence A097596 A054191 
               A079975
%Y A088813 Adjacent sequences: A088810 A088811 A088812 this_sequence A088814 A088815 
               A088816
%K A088813 nonn
%O A088813 0,2
%A A088813 Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), Oct 19 2003