John Wallis, Arithmetica Infinitorum (Oxford, England: Leon Lichfield, 1656), page 182. Архивная копия от 24 апреля 2021 на Wayback Machine. Brouncker expressed, as a continued fraction, the ratio of the area of a circle to the area of the circumscribed square (i.e., 4/π). The continued fraction appears at the top of page 182 (roughly) as: ☐ = 1 1/2 9/2 25/2 49/2 81/2 &c, where the square denotes the ratio that is sought. (Note: On the preceding page, Wallis names Brouncker as: "Dom. Guliel. Vicecon, & Barone Brouncher" (Lord William Viscount and Baron Brouncker).)
Е. Ю. Смирнов.Фризы и цепные дроби (неопр.). МЦНМО (17 марта 2020). Дата обращения: 17 апреля 2020. Архивировано 21 апреля 2021 года.
John Wallis, Arithmetica Infinitorum (Oxford, England: Leon Lichfield, 1656), page 182. Архивная копия от 24 апреля 2021 на Wayback Machine. Brouncker expressed, as a continued fraction, the ratio of the area of a circle to the area of the circumscribed square (i.e., 4/π). The continued fraction appears at the top of page 182 (roughly) as: ☐ = 1 1/2 9/2 25/2 49/2 81/2 &c, where the square denotes the ratio that is sought. (Note: On the preceding page, Wallis names Brouncker as: "Dom. Guliel. Vicecon, & Barone Brouncher" (Lord William Viscount and Baron Brouncker).)