On Extremal Sets and Their Products in Finite Intervals of Integers

In the present paper, we improve the lower bound for the size of an integer set $$A$$ in a finite interval such that the cardinality of the product $$AA$$ behaves asymptotically as $$|A|^2/2$$ . The main result presented here improves previous corresponding results of the papers [1] and [2] and uses additional arguments.