$(a,a)$-Carmichael numbers and greatest common divisors of $p-a$
Number Theory
2026-07-02 v1
Abstract
Define an -Carmichael number to be a squarefree natural number such that implies . For such a number with prime factors , define and let denote the number of -Carmichael numbers up to such that . Assuming a strong conjecture on the first prime in an arithmetic progression, we prove that for any integer and for any natural number with and and having opposite parity, This is a departure from many traditional constructions of Carmichael numbers, which generally require to grow along with .
Keywords
Cite
@article{arxiv.2607.02738,
title = {$(a,a)$-Carmichael numbers and greatest common divisors of $p-a$},
author = {Thomas Wright},
journal= {arXiv preprint arXiv:2607.02738},
year = {2026}
}
Comments
This is a significant revision and generalization of arXiv:2409.16397, since that paper is now largely subsumed by Larsen's result on Carmichael numbers in arithmetic progressions