English

A q-analog of Ljunggren's binomial congruence

Number Theory 2011-03-17 v1 Combinatorics

Abstract

We prove a qq-analog of a classical binomial congruence due to Ljunggren which states that (apbp)(ab) \binom{a p}{b p} \equiv \binom{a}{b} modulo p3p^3 for primes p5p\ge5. This congruence subsumes and builds on earlier congruences by Babbage, Wolstenholme and Glaisher for which we recall existing qq-analogs. Our congruence generalizes an earlier result of Clark.

Keywords

Cite

@article{arxiv.1103.3258,
  title  = {A q-analog of Ljunggren's binomial congruence},
  author = {Armin Straub},
  journal= {arXiv preprint arXiv:1103.3258},
  year   = {2011}
}

Comments

6 pages, to be published in the proceedings of FPSAC 2011