Cullen and Woodall numbers in Padovan and Perrin sequences
Number Theory
2026-05-25 v1
Abstract
Let and denote the Padovan and Perrin sequences, both satisfying the recurrence , but with initial values and , , , respectively. A \textit{Cullen number} is a positive integer of the form for some integer , while a \textit{Woodall number} is a positive integer of the form for some integer . In this paper, we determine all Woodall numbers in the Padovan sequence and all Cullen numbers in the Perrin sequence. Specifically, we prove that and are the only Woodall numbers in the Padovan sequence, and that is the only Cullen number in the Perrin sequence.
Cite
@article{arxiv.2605.23084,
title = {Cullen and Woodall numbers in Padovan and Perrin sequences},
author = {Herbert Batte and Eric F. Bravo and Florian Luca},
journal= {arXiv preprint arXiv:2605.23084},
year = {2026}
}
Comments
20 pages