Addition and multiplication of beta-expansions in generalized Tribonacci base

We study properties of β-numeration systems, where β > 1 is the real root of the polynomial x 3  - mx 2  - x - 1, m ∈ ℕ, m ≥ 1. We consider arithmetic operations on the set of β-integers, i.e., on the set of num...

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Bibliographic Details
Main Authors: Petr Ambrož, Zuzana Masáková, Edita Pelantová
Format: Article
Language:English
Published: Discrete Mathematics & Theoretical Computer Science 2007-05-01
Series:Discrete Mathematics & Theoretical Computer Science
Online Access:http://www.dmtcs.org/dmtcs-ojs/index.php/dmtcs/article/view/650
Description
Summary:We study properties of β-numeration systems, where β > 1 is the real root of the polynomial x 3  - mx 2  - x - 1, m ∈ ℕ, m ≥ 1. We consider arithmetic operations on the set of β-integers, i.e., on the set of numbers whose greedy expansion in base β has no fractional part. We show that the number of fractional digits arising under addition of β-integers is at most 5 for m ≥ 3 and 6 for m = 2, whereas under multiplication it is at most 6 for all m ≥ 2. We thus generalize the results known for Tribonacci numeration system, i.e., for m = 1. We summarize the combinatorial properties of infinite words naturally defined by β-integers. We point out the differences between the structure of β-integers in cases m = 1 and m ≥ 2.
ISSN:1462-7264
1365-8050