MathDB
Bounded expansive sequences

Source: KöMaL A. 713

February 13, 2018
algebraSequencepositive

Problem Statement

We say that a sequence a1,a2,a_1,a_2,\cdots is expansive if for all positive integers j,  i<jj,\; i<j implies aiaj1j|a_i-a_j|\ge \tfrac 1j. Find all positive real numbers CC for which one can find an expansive sequence in the interval [0,C][0,C].