MathDB
USAMO 2002 Problem 5

Source:

September 30, 2005
AMCUSA(J)MOUSAMOalgorithmDivisibility

Problem Statement

Let a,ba,b be integers greater than 2. Prove that there exists a positive integer kk and a finite sequence n1,n2,,nkn_1, n_2, \dots, n_k of positive integers such that n1=an_1 = a, nk=bn_k = b, and nini+1n_i n_{i+1} is divisible by ni+ni+1n_i + n_{i+1} for each ii (1i<k1 \leq i < k).