https://en.wikipedia.org/wiki/Steiner_chainhttps://en.wikipedia.org/wiki/Inversive_geometry#Circlehttps://en.wikipedia.org/wiki/Pappus_chainhttps://en.wikipedia.org/wiki/Circle_packing_theorem
Fractals and Steiner chains
https://codegolf.stackexchange.com/questions/80152/recursive-steiner-chains
