Cameron's Sum-Free Set Constant

A set of Positive Integers $S$ is sum-free if the equation $x+y=z$ has no solutions $x$, $y$, $z\in S$. The probability that a random sum-free set $S$ consists entirely of Odd Integers satisfies

$$0.21759\leq c\leq 0.21862.$$

References

Cameron, P. J. ``Cyclic Automorphisms of a Countable Graph and Random Sum-Free Sets.'' Graphs and Combinatorics 1, 129-135, 1985.

Cameron, P. J. ``Portrait of a Typical Sum-Free Set.'' In Surveys in Combinatorics 1987 (Ed. C. Whitehead). New York: Cambridge University Press, 13-42, 1987.

Finch, S. ``Favorite Mathematical Constants.'' http://www.mathsoft.com/asolve/constant/cameron/cameron.html