Periodic continued fraction

Continued fraction – Number represented as a0+1/(a1+1/...)

Generalized continued fraction – generalization of continued fractions in which the partial numerators and partial denominators can assume arbitrary complex values

Hermite's problem

Continued fraction method of computing square roots – Algorithms for calculating square roots

Restricted partial quotients – Analytic series

Continued fraction factorization – an integer factorization algorithm

https://en.wikipedia.org/wiki/Periodic_continued_fraction