English

Asymptotic $r$-log-convexity and P-recursive sequences

Combinatorics 2016-09-27 v1

Abstract

A sequence {an}n0\{ a_n \}_{n \ge 0} is said to be asymptotically rr-log-convex if it is rr-log-convex for nn sufficiently large. We present a criterion on the asymptotical rr-log-convexity based on the asymptotic behavior of anan+2/an+12a_n a_{n+2}/a_{n+1}^2. As an application, we show that most P-recursive sequences are asymptotic rr-log-convexity for any integer rr once they are log-convex. Moreover, for a concrete integer rr, we present a systematic method to find the explicit integer NN such that a P-recursive sequence {an}nN\{a_n\}_{n \ge N} is rr-log-convex. This enable us to prove the rr-log-convexity of some combinatorial sequences.

Keywords

Cite

@article{arxiv.1609.07840,
  title  = {Asymptotic $r$-log-convexity and P-recursive sequences},
  author = {Qing-Hu Hou and Zuo-Ru Zhang},
  journal= {arXiv preprint arXiv:1609.07840},
  year   = {2016}
}
R2 v1 2026-06-22T16:00:49.250Z