A088813 - OEIS

%I #10 Sep 29 2020 03:36:10

%S 1,2,4,7,14,26,43,79,137,246,398,733,1237,2314,3586,6730,11051,21096,

%T 31985,61654,102730,199555,301062,589746,942876,1858881,2793703,

%U 5524251,9193512,18256867,27396918,54517922,88020937,175434632,263194662,525173052

%N Number of subsets of {1, ..., n} that are double-free or sum-free.

%H Fausto A. C. Cariboni, <a href="/A088813/b088813.txt">Table of n, a(n) for n = 0..75</a>

%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/Double-FreeSet.html">Double-Free Set</a>

%H Eric Weisstein's World of Mathematics, <a href="http://mathworld.wolfram.com/Sum-FreeSet.html">Sum-Free Set</a>

%F a(n) = 2^n - A088812(n) = A050291(n)+A085489(n)-A007865(n).

%K nonn

%O 0,2

%A _Reinhard Zumkeller_, Oct 19 2003

%E Terms a(28) and beyond from _Fausto A. C. Cariboni_, Sep 29 2020