The sixth Fermat number and palindromic continued fractions (Q1347841)

The article shows in a elementary way how to factorize the sixth Fermat number \(2^6+1\). In the course of the factorization the author recalls the Serret theorem on palindromic continued fractions and proves it. This is an old, and probably not very much known theorem from elementary number theory. Though the theorem is in fact not necessary for the factorization (it offers an alternative method to solve one particular Diophantine equation), I think it is worth mentioning. This is a nice and easy-to-read article.