Large prime oscillator
A large prime oscillator is any oscillator with a relatively small bounding box whose period is a very large prime.
(If the bounding-box restriction is removed, then eight gliders travelling in a four-Snark loop or rectifier loop provides a trivial example for any sufficiently large prime. Most SKOPs for large prime periods are rectifier loops.[1])
The first such oscillator was built by Gabriel Nivasch on August 7, 2003.[2] The record holder for many years was an oscillator constructed by Adam P. Goucher in 2009 with a period that is a Mersenne prime with 13,395 digits (244497-1).[3][note 1]
The next record-holding oscillator was the next higher Mersenne-prime period, 286243-1. It was constructed with quadri-Snarks and semi-Snarks in November 2018. The pattern was posted by an unknown author in a comment on an unrelated Catagolue page.[note 2] It is actually less than a third of the size of the 244497-1 oscillator, due to the use of reasonably well-packed quadri-Snarks instead of semi-Snarks: 8875×4005 instead of 18493×7074.
On 16th July 2019, Dave Greene constructed an oscillator with period 282589933-1 by attaching a period-512 base gun to a compact rectangular region comprising 41294962 copies of the quadri-Snark. This is, as of the time of writing, the largest explicitly-known prime number.[4]
Notes
References
- ↑ Jeremy Tan (July 5, 2021). Re: Smallest Known Oscillators to p106 (and Beyond) (discussion thread) at the ConwayLife.com forums
- ↑ Jason Summers' jslife-oversize pattern collection. Retrieved on October 28, 2020.
- ↑ Adam P. Goucher (December 27, 2009). 13395-digit prime-period oscillator (discussion thread) at the ConwayLife.com forums
- ↑ Dave Greene (July 16, 2019). Re: Thread for basic questions (discussion thread) at the ConwayLife.com forums