Source: /cirosantilli/promys-europe-2024-problem-set/set-2/q2

= Q2

* <Greatest common divisor>{full}.
* <Farey sequence>{full}.
  * <Number of elements in a Farey sequence>{full}
  * <Farey sunburst>, e.g. $F_5$:
    \Image[https://upload.wikimedia.org/wikipedia/en/d/de/Sunburst_8.png]