Cameron's Sum-Free Set Constant

A set of positive integers  is called sum-free if the equation  has no solutions , , . The probability that a random sum-free set  consists entirely of odd integers is known to satisfy

The value of the constant  is Cameron's sum-free set constant.

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. R. "Cameron's Sum-Free Set Constant." §2.25 in Mathematical Constants. Cambridge, England: Cambridge University Press, pp. 180-183, 2003.