Caterer on Beluchenko's p13 is a period-39 oscillator discovered by Jason Summers in January 2009 that is composed of a caterer and a nearby Beluchenko's p13. With a minimum population of 46 cells, it is the smallest known period 39 oscillator, although jam on 34P13 (pictured below) has a smaller bounding box.
Even though it is made up of a period 3 oscillator and a period 13 oscillator, it is considered non-trivial because it has a single cell that oscillates at period 39 (it is alive in generation 11 but dead in the other 38 phases).
Generation 11 reveals the single cell that oscillates at the full period (in green)
Jam on Beluchenko's p13 with a smaller bounding box of 22×17Download RLE: click here
- 46P39.1 at Heinrich Koenig's Game of Life Object Catalogs