Nested For Loop
https://docs.google.com/presentation/d/1gcySt4Cj7uRxe69srLydJ6tz-Bc-QJCEtgd8UUtUm48/edit?usp=sharing
https://editor.p5js.org/Mustard-Roy/sketches/5_1GRZ_F2
Nested For Loop and Permutation Design Blog