Gabriel's p138 is a period 138 oscillator discovered by Gabriel Nivasch on October 13, 2002. In terms of its 36 cells, it is, by far, the smallest known period 138 oscillator. Within a month of its discovery, Jason Summers found a 12-glider synthesis for this oscillator.
- ↑ Jason Summers' all-osc pattern collection.
- ↑ Jason Summers' jslife pattern collection.
- 36P136.1 at Heinrich Koenig's Game of Life Object Catalogs (note: site incorrectly lists period as 136 instead of 138)