首页 | 本学科首页   官方微博 | 高级检索  
     检索      


On an inequality of Ramanujan concerning the prime counting function
Authors:Mehdi Hassani
Institution:1. Department of Mathematics, University of Zanjan, P.O. Box 313, 45371-38111, Zanjan, Iran
Abstract:We discuss on the sign of $\mathcal{R}_{\alpha }(x):=\pi(x)^{2}-\frac{\alpha x}{\log x}\pi(\frac{x}{\alpha })$ for x sufficiently large, and for various values of ??>0. The case ??=e refers to a result due to Ramanujan asserting that $\mathcal{R}_{e}(x)<0$ . Related by this inequality, we obtain a conditional result that gives the number N>530.2 such that $\mathcal{R}_{e}(x)<0$ is valid for x>e N . Moreover, we show that under assumption of validity of the Riemann hypothesis, the inequality $\mathcal{R}_{e}(x)<0$ holds for x>138,766,146,692,471,228. Then, in various cases for ??, we find numerical values of x ?? in which $\mathcal{R}_{\alpha }(x)$ is strictly positive or negative for x??x ?? .
Keywords:
本文献已被 SpringerLink 等数据库收录!
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号