Figure eight on pentadecathlon is a period 120oscillator composed of a figure eight and pentadecathlon. Although it is composed of two oscillators of smaller periods (8 and 15 respectively), it is considered nontrivial, because it contains one cell that is alive in generation 95 and dead in the other 119 phases of the oscillator. In terms of its 24 cells, it is the smallest known nontrivial period120 oscillator.
There is a variant of this oscillator with a slightly larger bounding box, and two other 26cell variants which have 3 cells with period 120.
Image gallery
Generation 95 reveals the single cell with period 120 (in green)
The 26cell variant, showing 2 of the 3 cells with period 120 (in green) Download RLE: click here

Generation 119 of the 26cell variant, showing the other cell with period 120 (in green)

See also
External links