Pentadecathlon on snacker is a period-45oscillator composed of a pentadecathlon and a snacker. Although it is composed of two oscillators of smaller periods (15 and 9 respectively), it is considered to be non-trivial, because it has two cells that oscillate at the full period. It was the first non-trivial period 45 oscillator to be discovered and was discovered sometime before August 1995.
There have been two occurrences in D4_+2-symmetric soups found by Charity Engine. On March 4, 2022, a variant of this oscillator (with integrals instead of eaters and a pentadecathlon on either side) appeared, making it the first semi-natural p45 oscillator,[1] and on September 15, 2022, the canonical version (albeit still with two pentadecathlons) appeared in another.[2]
Gallery
Generation 5 reveals the two cells that oscillate at the full period (in green)
An alternate form of pentadecathlon on snacker, with a slightly smaller bounding box of 20 × 18 (click above to open LifeViewer) RLE:herePlaintext:here