Rogers-Ramanujan continued fraction and approximations to $\mathbf{2\pi}$
Number Theory
2023-08-22 v1
Abstract
We observe that certain famous evaluations of the Rogers-Ramanujan continued fraction are close to and , and that can be expressed by a Rogers-Ramanujan continued fraction in which is very nearly equal to . The value of converges to as increases. For , a modular equation by Ramanujan provides recursive closed-form expressions that approximate the value of , the number of correct digits increasing by a factor of five each time increases by one. If we forgo closed-form expressions, a modular equation by Rogers allows numerical iterations that converge still faster to , each iteration increasing the number of correct digits by a multiple of eleven.
Keywords
Cite
@article{arxiv.2308.09774,
title = {Rogers-Ramanujan continued fraction and approximations to $\mathbf{2\pi}$},
author = {Rajeev Kohli},
journal= {arXiv preprint arXiv:2308.09774},
year = {2023}
}