TL ; DR
This is an exercice we did at school, which I went further into. It's a Cellular automaton which you can change the birth and surviving rules.
- Press "P" to pause and hold "A" to set the initial birth on 0.
- Change the rules to B: 1,3 and S: 1,3
- Press "R" to reset the grid, click on a cell and press "P" to resume the automaton.
- Enjoy the living mandala!