CollapseProblem 749Let ϵ>0\epsilon>0ϵ>0. Does there exist A⊆NA\subseteq \mathbb{N}A⊆N such that the lower density of A+AA+AA+A is at least 1−ϵ1-\epsilon1−ϵ and yet 1A∗1A(n)≪ϵ11_A\ast 1_A(n) \ll_\epsilon 11A∗1A(n)≪ϵ1 for all nnn?Source: erdosproblems.com/749Additive combinatoricsWiki pageStatusOpenNo claim settles this problem.ReferencesEr94bErdős, Paul, Some problems in number theory, combinatorics and combinatorial geometry. Math. Pannon. (1994), 261-269.