The density of primes dividing a particular non-linear recurrence sequence
Number Theory
2018-01-22 v2
Abstract
Define the sequence by , and b_n=\begin{cases} \frac{b_{n-1}b_{n-3}-b_{n-2}^2}{b_{n-4}}&\textrm{if}~ n\not\equiv 0\pmod 3, \frac{b_{n-1}b_{n-3}-3b_{n-2}^2}{b_{n-4}}&\textrm{if}~ n\equiv 0\pmod 3. We relate this sequence to the coordinates of points on the elliptic curve . We use Galois representations attached to to prove that the density of primes dividing a term in this sequence is equal to . Furthermore, we describe an infinite family of elliptic curves whose Galois images match that of .
Cite
@article{arxiv.1508.02464,
title = {The density of primes dividing a particular non-linear recurrence sequence},
author = {Alexi Block Gorman and Tyler Genao and Heesu Hwang and Noam Kantor and Sarah Parsons and Jeremy Rouse},
journal= {arXiv preprint arXiv:1508.02464},
year = {2018}
}
Comments
23 pages, with an appendix giving an alternative definition of the sequence