Two Lower Bounds for Shortest Double-Base Number System

Abstract

In this letter, we derive two lower bounds for the number of terms in a double-base number system (DBNS), when the digit set is {1}. For a positive integer n, we show that the number of terms obtained from the greedy algorithm proposed by Dimitrov, Imbert, and Mishra [1] is $\Theta\left(\frac{\log n}{\log \log n}\right)$. Also, we show that the number of terms in the shortest double-base chain is Θ(log n).