does not have a limit as x tends to infinity; more precisely the limit superior is greater than 1, and the limit inferior is less than 1. The Cramér model of primes predicts incorrectly that it has limit 1 when λ ≥ 2 (using the Borel–Cantelli lemma).
Proofs
Maier proved his theorem using Buchstab's equivalent for the counting function of quasi-primes (set of numbers without prime factors lower to bound , fixed). He also used an equivalent of the number of primes in arithmetic progressions of sufficient length due to Gallagher.
Pintz (2007) gave another proof, and also showed that most probabilistic models of primes incorrectly predict the mean square error
Soundararajan, K. (2007), "The distribution of prime numbers", in Granville, Andrew; Rudnick, Zeév (eds.), Equidistribution in number theory, an introduction. Proceedings of the NATO Advanced Study Institute on equidistribution in number theory, Montréal, Canada, July 11--22, 2005, NATO Science Series II: Mathematics, Physics and Chemistry, vol. 237, Dordrecht: Springer-Verlag, pp. 59–83, ISBN978-1-4020-5403-7, Zbl1141.11043