A088813 Number of subsets of {1, ..., n} that are double-free or sum-free.

1, 2, 4, 7, 14, 26, 43, 79, 137, 246, 398, 733, 1237, 2314, 3586, 6730, 11051, 21096, 31985, 61654, 102730, 199555, 301062, 589746, 942876, 1858881, 2793703, 5524251, 9193512, 18256867, 27396918, 54517922, 88020937, 175434632, 263194662, 525173052

Offset: 0

Author

Reinhard Zumkeller, Oct 19 2003

Keywords

• nonn

Links

• Fausto A. C. Cariboni, Table of n, a(n) for n = 0..75
• Eric Weisstein's World of Mathematics, Double-Free Set
• Eric Weisstein's World of Mathematics, Sum-Free Set

Formula

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

Extensions

Terms a(28) and beyond from Fausto A. C. Cariboni, Sep 29 2020