Pentoad
| Pentoad | |||||||||
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| Pattern type | Oscillator | ||||||||
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| Number of cells | 20 | ||||||||
| Bounding box | 13 × 12 | ||||||||
| Period | 5 (mod: 5) | ||||||||
| Heat | 8.8 | ||||||||
| Volatility | 0.65 | 0.65 | ||||||||
| Kinetic symmetry | Unspecified | ||||||||
| Discovered by | Bill Gosper | ||||||||
| Year of discovery | 1977 | ||||||||
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Pentoad (or eater-bound Z-hexomino[1]) is a period-5 oscillator that was found by Bill Gosper in June 1977. It consists of a Z-hexomino that is stabilized by two eater 1s.
It was discovered by Scott Kim that this oscillator is extensible by moving one of the eaters diagonally away by four cells and inserting another Z-hexomino in the gap.[2] A pentoad constructed in this way with n Z-hexominoes has 14 + 6n cells and heat 8.8 + 6.4n. The pentoad with two Z-hexominoes is shown below.
goldenratio found a 10-glider synthesis of this oscillator on September 3, 2020.[3]
Gallery
| Pentoad with two Z-hexominoes (click above to open LifeViewer) RLE: here Plaintext: here |
Pentoad 2
Pentoad 2 is a period-5 oscillator that is shown as the second pattern in the sixth row of Jason Summers' main period 5 collection. It is extensible. The central part is the same as in pentoad.
A 16-glider synthesis was found by Jeremy Tan on March 19, 2019,[4] which was later improved to 12 gliders by Goldtiger997.[5]
This oscillator first appeared semi-naturally in September 2016.[6]
| An fairly common alternate stabilization of pentoad, named pentoad 2 (click above to open LifeViewer) RLE: here Plaintext: here |
Pentoad 1H2
Pentoad 1H2 is a period-5 oscillator that is a hybrid of pentoad and pentoad 2. It is extensible in a similar manner. The '1' and '2' in the name refer to the types of pentoad ends in the pattern. The 'H' refers to the one hexomino in middle.
Mark Niemiec found a 19-glider synthesis for this oscillator on August 29, 2013,[7] which MathAndCode improved to 13 gliders on January 17, 2021.[8]
| A hybrid version of the two stabilizations, named pentoad 1H2 (click above to open LifeViewer) RLE: here Plaintext: here |
See also
References
- ↑ Mark D. Niemiec. "Eater-bound Z-hexomino glider synthesis RLE file". Retrieved on April 28, 2009.
- ↑ Dean Hickerson's oscillator stamp collection. Retrieved on March 14, 2020.
- ↑ goldenratio (September 3, 2020). Re: Synthesising Oscillators (discussion thread) at the ConwayLife.com forums
- ↑ Jeremy Tan (March 19, 2019). Re: Synthesising Oscillators (discussion thread) at the ConwayLife.com forums
- ↑ Goldtiger997 (April 1, 2019). Re: Synthesising Oscillators (discussion thread) at the ConwayLife.com forums
- ↑ Apple Bottom (September 11, 2016). Re: Soup search results (discussion thread) at the ConwayLife.com forums
- ↑ Mark Niemiec (August 31, 2013). Re: Synthesising Oscillators (discussion thread) at the ConwayLife.com forums
- ↑ MathAndCode (January 17, 2021). Re: Synthesising Oscillators (discussion thread) at the ConwayLife.com forums
External links
- Pentoad at the Life Lexicon
- Pentoad at Adam P. Goucher's Catagolue
- 20P5.9 at Heinrich Koenig's Game of Life Object Catalogs
- Pentoad 2 at Adam P. Goucher's Catagolue
- Pentoad 2 at Heinrich Koenig's Game of Life Object Catalogs
- Pentoad 1H2 at Adam P. Goucher's Catagolue
- Pentoad 1H2 at Heinrich Koenig's Game of Life Object Catalogs
- Patterns
- Oscillators with 20 cells
- Periodic objects with minimum population 20
- Patterns with 20 cells
- Patterns found by Bill Gosper
- Patterns found in 1977
- Patterns that can be constructed with 10 gliders
- Oscillators
- Oscillators with period 5
- Oscillators with mod 5
- Oscillators with heat 8
- Oscillators with volatility 0.65
- Oscillators with strict volatility 0.65
- Patterns with 180-degree rotation symmetry
- Semi-natural periodic objects