MathDB
Miklos Schweitzer 1950_1

Source: first round of 1950

October 2, 2008
algebra proposedalgebra

Problem Statement

Let \{k_n\}_{n \equal{} 1}^{\infty} be a sequence of real numbers having the properties k1>1 k_1 > 1 and k_1 \plus{} k_2 \plus{} \cdots \plus{} k_n < 2k_n for n \equal{} 1,2,.... Prove that there exists a number q>1 q > 1 such that kn>qn k_n > q^n for every positive integer n n.