MathDB
Integer Area in bounded by inequalities

Source: 2015 AIME I Problem 14

March 20, 2015
geometryanalytic geometryinequalities

Problem Statement

For each integer n2n \ge 2, let A(n)A(n) be the area of the region in the coordinate plane defined by the inequalities 1xn1\le x \le n and 0yxx0\le y \le x \left\lfloor \sqrt x \right\rfloor, where x\left\lfloor \sqrt x \right\rfloor is the greatest integer not exceeding x\sqrt x. Find the number of values of nn with 2n10002\le n \le 1000 for which A(n)A(n) is an integer.