Replicators: B01378/S123

B01378/S123 has a period-26 replicator, formed by three dominos, that moves at speed 9c/26.

It also contains a small puffer that leaves a trail of staggered dots.

When this rule is run with random initial conditions, the space fills up with scattered oscillators (primarily single dots) that prevent replicators from spreading. If the initial density of live cells is approximately 43%, regions that have live cells on a dead background on even steps are separated from regions with the opposite parity by chaotic boundaries that anneal slowly; with other initial densities, one phase or the other eventually takes over the whole space.

Replicators -- Cellular Automata -- D. Eppstein -- UCI Inf. & Comp. Sci.