A classical combinatorial number theory problem is to determine the maximum size of a Sidon set {1,2,…,n}, where subset integers if all its pairwise sums are different. For this entry point into subject, combining two elementary proofs, we decrease gap between upper and lower bounds by 0.2% for infinitely many values n. We show that {1,2,…,n} at most n+0.998n1/4 n sufficiently large.