A Family of Continued Fractions for Ratios of Zeta Values
Authors/Creators
Abstract
The Ramanujan Machine project has catalogued many conjectural continued fraction identities involving zeta constants.
In this paper we present a unified construction that produces a family of continued fractions whose limits are rational combinations of zeta values.
For any integer $m\ge 2$ and a suitably chosen polynomial $R$, we obtain a continued fraction with partial numerators $b_n=-n^{2m}$ and partial denominators $a_n$ given by a simple rule, and we prove that its value is
\[
\Bigl( \frac1{R(0)}+\sum_{k=1}^\infty \frac1{(k+1)^m R(k)R(k-1)}\Bigr)^{-1}.
\]
By selecting $R$ appropriately, this family produces closed forms such as
\[
-\frac{1}{\zeta(4)+4\zeta(2)-8},\qquad
\frac{2}{2\zeta(5)+6\zeta(3)-9},\qquad
\frac{2}{2\zeta(5)-2\zeta(3)+1}.
\]
The proof uses an explicit factorial--polynomial closed form for the numerator sequence, a telescoping difference equation, and elementary partial fraction techniques.
The results confirm several identities proposed by the Ramanujan Machine (after correcting suspected typographical errors in the original conjectures).
We also present a natural one‑parameter extension that yields families depending on an additional scale parameter $c$, which contains the original family as the special case $c=1$.
Notes (English)
Methods (English)
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The author used LLM in this article. The interaction history is provided in AI_Interaction_Logs.zip.
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Additional details
Additional titles
- Subtitle (English)
- Extending Conjectures of the Ramanujan Machine
Related works
- Cites
- Journal article: 10.1038/s41586-021-03229-4 (DOI)
- Other: http://www.ramanujanmachine.com/wp-content/uploads/2022/07/results_different_zeta_orders.pdf (URL)
- Publication: 10.5281/zenodo.20456395 (DOI)
References
- G. Raayoni, S. Gottlieb, Y. Manor, et al., Generating conjectures on fundamental constants with the Ramanujan Machine, Nature 590 (2021), 67–73.
- The Ramanujan Machine Project, Results using mixed orders of ζ, July 2022. http://www.ramanujanmachine.com/wp-content/uploads/2022/07/results_different_zeta_orders.pdf (archived at https://web.archive.org/web/20260601143653/http%3A%2F%2Fwww.ramanujanmachine.com%2Fwp-content%2Fuploads%2F2022%2F07%2Fresults_different_zeta_orders.pdf).
- L. Gao, A Family of Continued Fractions with Closed Forms (Version 2), Zenodo, 2026. https://doi.org/10.5281/zenodo.20456395