MathDB
IMO Shortlist 2009 - Problem N6

Source:

July 5, 2010
algebrapolynomialSequencenumber theoryDivisibilityIMO Shortlist

Problem Statement

Let kk be a positive integer. Show that if there exists a sequence a0,a1,a_0,a_1,\ldots of integers satisfying the condition an=an1+nkn for all n1,a_n=\frac{a_{n-1}+n^k}{n}\text{ for all } n\geq 1, then k2k-2 is divisible by 33.
Proposed by Okan Tekman, Turkey