IMO 2010 Shortlist A4

A sequence x1,x2,... is defined by x1  1 and x2k  xk, x2k1  p1qk 1 xk for all k ©1. Prove that x1 x2  xn ©0 for...

IMO 2010 Shortlist A4

Category: Algebra

Problem

A sequence x1,x2,... is defined by x1  1 and x2k  xk, x2k1  p1qk 1 xk for all k ©1. Prove that x1 x2  xn ©0 for all n ©1. (Austria)