PreprintarXiv licencearXiv
An improvement on the largest prime factor of n2+1
Abstract
The study of the largest prime factor in polynomial sequences can be traced back at least to the late 19th century in the work of Störmer. Mahler (1933) and Chowla (1934) proved that the largest prime factor of n2+1 grows at least as fast as log2 n. In 2023 we improved this to (log2 n)2/log3 n. In this note we show the lower bound (log2 n)2/log4 n, and that when this bound is nearly sharp it also holds for many prime factors of n2+1.
Related
- On the largest prime factors of p−1 and p+1
- Rigidity of Averages over the Two Largest Prime Factors
- Note on the largest prime factors of consecutive integers
- On the largest prime factors less than y of consecutive shifted primes
- Ordinary 3-Isogeny Graphs and Improvement of Supersingularity Testing for Twisted Hessian Curves over Prime Fields
BibTeX
@misc{pasten2026improvement,
title = {{An improvement on the largest prime factor of $n^2+1$}},
author = {Hector Pasten},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2609.01327},
eprint = {2609.01327},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2609.01327},
}
RIS
TY - UNPB
TI - An improvement on the largest prime factor of n^2+1
AU - Hector Pasten
PY - 2026
DA - 2026/09/01
PB - arXiv
DO - 10.48550/arxiv.2609.01327
UR - https://arxiv.org/abs/2609.01327
AB - The study of the largest prime factor in polynomial sequences can be traced back at least to the late 19th century in the work of Störmer. Mahler (1933) and Chowla (1934) proved that the largest prime factor of n^2+1 grows at least as fast as log_2 n. In 2023 we improved this to (log_2 n)^2/log_3 n. In this note we show the lower bound (log_2 n)^2/log_4 n, and that when this bound is nearly sharp it also holds for many prime factors of n^2+1.
ER -