A088811 Number of subsets of {1, ..., n} that are sum-free but not double-free.

0, 0, 1, 1, 4, 6, 13, 19, 41, 54, 110, 157, 277, 394, 706, 970, 1691, 2376, 3905, 5494, 9130, 12355, 20262, 28146, 44316, 61761, 98023, 132891, 207912, 285667, 440118, 604322, 929737, 1252232, 1921062, 2625852, 3933025, 5351483, 8085728, 10856110

Offset

0,5

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

Reinhard Zumkeller, Illustration of initial terms

Formula

a(n) = A088808(n) - A088812(n) = A085489(n) - A007865(n).

Crossrefs

Sequence in context: A247284 A069061 A373945 * A007977 A013122 A012964

Adjacent sequences: A088808 A088809 A088810 * A088812 A088813 A088814

Keyword

nonn

Author

Reinhard Zumkeller, Oct 19 2003

Extensions

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

Status

approved