English

Uniform Recurrence in the Motzkin Numbers and Related Sequences mod $p$

Combinatorics 2024-03-04 v1 Number Theory

Abstract

Many famous integer sequences including the Catalan numbers and the Motzkin numbers can be expressed in the form ConstantTermOf[P(x)nQ(x)]ConstantTermOf\left[P(x)^nQ(x)\right] for Laurent polynomials QQ, and symmetric Laurent trinomials PP. In this paper we characterize the primes for which sequences of this form are uniformly recurrent modulo pp. For all other primes, we show that 00 has density 11. This will be accomplished by showing that the study of these sequences mod pp can be reduced to the study of the generalized central trinomial coefficients, which are well-behaved mod pp.

Keywords

Cite

@article{arxiv.2403.00149,
  title  = {Uniform Recurrence in the Motzkin Numbers and Related Sequences mod $p$},
  author = {Nadav Kohen},
  journal= {arXiv preprint arXiv:2403.00149},
  year   = {2024}
}

Comments

10 pages, 1 figure