On a Problem of Erdős and Sárközy

Let A={a1, a2, …}⊆N and put A(n)=∑ai⩽n 1. We say that A is a P-set if no element ai divides the sum of two larger elements. It is proved that for every P-set A with pairwise co-prime elements the inequality A(n)<2n2/3 holds for infinitely many n∈N.