Source: 2010 China South East Mathematical Olympiad
July 18, 2011
algebra unsolvedalgebra
Problem Statement
Let N∗ be the set of positive integers. Define a1=2, and for n=1,2,…,an+1=min{λ∣a11+a21+⋯an1+λ1<1,λ∈N∗}
Prove that an+1=an2−an+1 for n=1,2,….