Une forme effective d'un thééorèème de Bateman sur la fonction phi d'Euler.

Let ΦΦ( x) be the number of the integers n such that φφ( n) ≤≤ x, where φφ denotes the Euler function. In this paper we give an explicit form of Bateman's theorem for the remainder term ΦΦ( x) -- Ax where A == ζζ(2) ζζ(3)/ ζζ(6). [ABSTRACT FROM AUTHOR]