English

On a Ramanujan-type series associated with the Heegner number 163

Number Theory 2024-02-14 v1

Abstract

Using the Wolfram NumberTheory package and the Recognize command, together with numerical estimates involving the elliptic lambda and elliptic alpha functions, Bagis and Glasser, in 2013, introduced a conjectural Ramanujan-type series related to the class number h(d)=1h(-d) = 1 for a quadratic form with discriminant d=163d = 163. This conjectured series is of level one and has positive terms, and recalls the Chudnovsky brothers' alternating series of the same level, given the connection between the Chudnovsky-Chudnovsky formula and the Heegner number d=163d = 163 such that Q(d)\mathbb{Q}\left( \sqrt{-d} \right) has class number one. We prove Bagis and Glasser's conjecture by proving evaluations for λ(163)\lambda^{\ast}(163) and α(163)\alpha(163), which we derive using the Chudnovsky brothers' formula together with the analytic continuation of a formula due to the Borwein brothers for Ramanujan-type series of level one. As a byproduct of our method, we obtain an infinite family of Ramanujan-type series for 1π\frac{1}{\pi} generalizing the Chudnovsky algorithm.

Keywords

Cite

@article{arxiv.2402.08485,
  title  = {On a Ramanujan-type series associated with the Heegner number 163},
  author = {John M. Campbell},
  journal= {arXiv preprint arXiv:2402.08485},
  year   = {2024}
}

Comments

To appear in the Journal of Number Theory