English

Binomial coefficients, roots of unity and powers of prime numbers

Number Theory 2022-03-08 v1

Abstract

Let tN+t\in\mathbb{N}_+ be given. In this article we are interested in characterizing those dN+d\in\mathbb{N}_+ such that the congruence 1ts=0t1(n+dζtsd1)(nd1)(modd)\frac{1}{t}\sum_{s=0}^{t-1}{n+d\zeta_t^s\choose d-1}\equiv {n\choose d-1}\pmod{d} is true for each nZn\in\mathbb{Z}. In particular, assuming that dd has a prime divisor greater than tt, we show that the above congruence holds for each nZn\in\mathbb{Z} if and only if d=prd=p^r, where pp is a prime number greater than tt and r{1,,t}r\in\{1,\ldots ,t\}.

Keywords

Cite

@article{arxiv.2203.03281,
  title  = {Binomial coefficients, roots of unity and powers of prime numbers},
  author = {Piotr Miska},
  journal= {arXiv preprint arXiv:2203.03281},
  year   = {2022}
}

Comments

Accepted to Bulletin of the Malaysian Mathematical Sciences Society