Art of Problem Solving
AoPS Online
Math texts, online classes, and more
for students in grades 5-12.
Visit AoPS Online ‚
Books for Grades 5-12 Online Courses
Beast Academy
Engaging math books and online learning
for students ages 8-13.
Visit Beast Academy ‚
Books for Ages 8-13 Beast Academy Online
AoPS Academy
Nationwide learning centers
for students in grades 2-12.
Visit AoPS Academy ‚
Find a Physical Campus Visit the Virtual Campus

2002 IMO Problems/Problem 4

Problem: Let $n>1$ be an integer and let $1=d_{1}<d_{2}<d_{3} \cdots <d_{r}=n$ be all of its positive divisors in increasing order. Show that \[d=d_1d_2+d_2d_3+ \cdots +d_{r-1}d_r <n^2\]

Solution 1

Retrieved from "https://artofproblemsolving.com/wiki/index.php?title=2002_IMO_Problems/Problem_4&oldid=194423"
Invalid username
Login to AoPS