Links for Steiner Chains
https://en.wikipedia.org/wiki/Steiner_chain https://en.wikipedia.org/wiki/Inversive_geometry#Circle https://en.wikipedia.org/wiki/Pappus_chain https://en.wikipedia.org/wiki/Circle_packing_theorem Fractals and Steiner chains https://codegolf.stackexchange.com/questions/80152/recursive-steiner-chains