Sum of Neighbours cellular automaton with triangular cells. The value of each cell at iteration N+1 is the sum of the values of all its edge-neighbours at iteration N, unless the total is more than 100, in which case it reverts to 1. See many more cellular automata videos at https://www.youtube.com/playlist?list=PLIOE8d0M72z7L-EZFEWc28pXTEcFNGWG4