... is (k, )-sum-free for k, ∈ N, k>,ifthereare no solutions to the equation x1+ ···+ xk= y1+ ···+ yin A. Denoteby SFnk, the number of (k, )-sum-free subsets of [1,n]. Since the ... ρ). The main result of this note says that if (k − )/ is small in terms of ρ, then the number of (k, )-sum-free subsets of [1,n]isequalto(ϕ(ρ)+ϕr(ρ)+o(1))2n/ρ,where ϕr(x) denotes the ... com-ments. Due to their suggestions we were able to prove the main result of the note in its present sharp form. the electronic journal of combinatorics 7 (2000), #R30 2odd numbers is (2, 1)-sum-free...