English

The abc Conjecture Implies That Only Finitely Many s-Cullen Numbers Are Repunits

Number Theory 2021-05-27 v4

Abstract

Assuming the abc conjecture with ϵ=1/6\epsilon=1/6, we use elementary methods to show that only finitely many ss-Cullen numbers are repunits, aside from two known infinite families. More precisely, only finitely many positive integers ss, nn, bb, and qq with s,b2s,b \geq 2 and n,q3n,q \geq 3 satisfy Cs,n=nsn+1=bq1b1.C_{s,n} = ns^n + 1 = \frac{b^q -1}{b-1}.

Keywords

Cite

@article{arxiv.2009.04052,
  title  = {The abc Conjecture Implies That Only Finitely Many s-Cullen Numbers Are Repunits},
  author = {Jon Grantham and Hester Graves},
  journal= {arXiv preprint arXiv:2009.04052},
  year   = {2021}
}

Comments

v4: fixed typo, added journal reference v3: Significantly improved the main result v2: Improved formatting, better Masser reference