Sharp bounds for psi function

作者：

Highlights：

•

摘要

In this paper, we present the greatest value a ∈ (1/15, ∞) and the least value b ∈ (4/15, ∞) such that the double inequality L(x,a)<ψ(x+1) 0, where L(x,a)=190a2+2log(x2+x+3a+13)+45a290a2+2log(x2+x+15a−145a) and ψ(x) is the classical psi function.

论文关键词：Gamma function,Psi function,Monotonicity

论文评审过程：Received 3 January 2015, Revised 26 March 2015, Accepted 5 July 2015, Available online 25 July 2015, Version of Record 25 July 2015.

论文官网地址：https://doi.org/10.1016/j.amc.2015.07.012