Skip to main content
Log in

Some Quicker Approximations and Inequalities of the Wallis Ratio by Continued Fraction

  • Published:
Results in Mathematics Aims and scope Submit manuscript

Abstract

In this paper, we present a new formula for approximating the Wallis ratio. This new formula is very fast in comparison with other classical or recently discovered asymptotic series. Next, inequalities related to this new formula and asymptotic series are established. Finally, for demonstrating the superiority of our new series, some numerical computations are provided.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Similar content being viewed by others

References

  1. Alzer H.: On some inequalities for the gamma and psi functions. Math. Comput. 66(217), 373–389 (1997)

    Article  MathSciNet  Google Scholar 

  2. Chen C.-P., Qi F.: The best bounds in Wallis’ inequality. Proc. Am. Math. Soc. 133(2), 397–401 (2005)

    Article  MathSciNet  Google Scholar 

  3. Guo, S., Xu, J.-G., Qi, F.: Some exact constants for the approximation of the quantity in the Wallis’ formula. J. Inequal. Appl. 2013, 67 (2013)

    Article  MathSciNet  Google Scholar 

  4. Mortici C.: Product approximations via asymptotic integration. Am. Math. Mon. 117, 434–441 (2010)

    Article  MathSciNet  Google Scholar 

  5. Mortici C.: A new Stirling series as continued fraction. Numer. Algorithms 56(1), 17–26 (2011)

    Article  MathSciNet  Google Scholar 

  6. Mortici C.: A continued fraction approximation of the gamma function. J. Math. Anal. Appl. 402(2), 405–410 (2013)

    Article  MathSciNet  Google Scholar 

  7. Mortici, C.: A new fast asymptotic series for the gamma function. J. Ramanujan. doi:10.1007/s11139-014-9589-0 (2015, online)

  8. Qi F., Mortici C.: Some best approximation formulas and inequalities for the Wallis ratio. App. Math. Comput. 253, 363–368 (2015)

    Article  MathSciNet  Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Lixin Song.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Liu, X., Lu, D. & Song, L. Some Quicker Approximations and Inequalities of the Wallis Ratio by Continued Fraction. Results. Math. 70, 325–335 (2016). https://doi.org/10.1007/s00025-015-0509-4

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s00025-015-0509-4

Mathematics Subject Classification

Keywords

Navigation