Recursion for A-level (Cambridge syllabus)
See my brand new intro to recursion at: • How to use Recursion in Python!
This guide to recursion in Python shows you how step by step what recursion is about and goes through several examples.
The Grey Code: https://en.wikipedia.org/wiki/Gray_code
Further challenges:
https://pythonturtle.academy/category...
https://introcs.cs.princeton.edu/java... (Java based, but still doable in Python)