Archiv der Mathematik

, Volume 89, Issue 5, pp 411–418

A note on the Ramanujan τ-function


DOI: 10.1007/s00013-007-2246-8

Cite this article as:
Garaev, M.Z., Garcia, V.C. & Konyagin, S.V. Arch. Math. (2007) 89: 411. doi:10.1007/s00013-007-2246-8


Let τ(n) be the Ramanujan τ-function, x ≥ 10 be an integer parameter. We prove that
$$\# \{ \tau (n):n\, \leqslant\, x \} \gg x^{1/2} e^{ - 4\log x/ {\rm log} \log x}$$
We also show that
$$ \omega \left( {\mathop \prod \limits_{\begin{array}{*{20}c} {p \leqslant x} \\ {\tau (p) \ne 0} \\ \end{array} } \tau (p)\tau (p^2 )} \right) \gg \frac{{(\log x)^{13/11} }} {{\log \log x}}, $$
where ω(n) is the number of distinct prime divisors of n and p denotes prime numbers. These estimates improve several results from [6, 9].

Mathematics Subject Classification (2000).



Ramanujan τ-functionvalue setprime factors

Copyright information

©  2007

Authors and Affiliations

  1. 1.Instituto de MatemáticasUniversidad Nacional Autónoma de MéxicoMoreliaMéxico
  2. 2.Department of Mechanics and MathematicsMoscow State UniversityMoscowRussia