A088810 Number of subsets of {1, ..., n} that are double-free but not sum-free.

0, 0, 0, 0, 1, 4, 6, 18, 35, 84, 137, 323, 591, 1313, 2033, 4360, 7406, 15581, 23682, 49184, 84017, 171744, 259818, 528784, 853143, 1727011, 2601181, 5243126, 8784832, 17662987, 26541257, 53279330, 86241323, 172871156, 259534578, 519917139

Offset

0,6

Links

Fausto A. C. Cariboni, Table of n, a(n) for n = 0..88

Eric Weisstein's World of Mathematics, Double-Free Set

Eric Weisstein's World of Mathematics, Sum-Free Set

Reinhard Zumkeller, Illustration of initial terms

Formula

a(n) = A050291(n) - A007865(n) = A088809(n) - A088812(n).

Crossrefs

Sequence in context: A156096 A281861 A218898 * A005199 A107390 A051253

Adjacent sequences: A088807 A088808 A088809 * A088811 A088812 A088813

Keyword

nonn,changed

Author

Reinhard Zumkeller, Oct 19 2003

Extensions

Terms a(28) and beyond from Fausto A. C. Cariboni, Sep 27 2020

Status

approved