The Cameron-Erdos conjecture

A subset A of integers is said to be sum-free if a+b is not an element of A for any a, b is not an element of A. Lets(n) be the number of sum-free sets in interval [1,n] of integers. P. Cameron and R Erdos conjectured that s(n) = O(2(n)/(2)). We show that s(n) similar to c(0)2(n/2) for even it and s(n) similar to c(1)2(n/2) for odd it, where 0, l are absolute constants, (hereby proving the conjecture. (C) 2007 Elsevier B.V. All rights reserved.