Pentoad
From LifeWiki
Pentoad  
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Pattern type  Oscillator  

Number of cells  20  
Bounding box  13×12  
Period  5  
Mod  5  
Heat  8.8  
Volatility  0.65  
Strict volatility  0.65  
Discovered by  Bill Gosper  
Year of discovery  1977  
 
 
 

Pentoad (or eaterbound Zhexomino^{[1]}) is a period 5 oscillator that was found by Bill Gosper in June 1977. It consists of a Zhexomino 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 Zhexomino in the gap. A pentoad constructed in this way with n Zhexominoes has 14 + 6n cells and heat 8.8 + 6.4n. The pentoad with two Zhexominoes is shown below.
Image gallery
See also
References
 ↑ Mark D. Niemiec. "Eaterbound Zhexomino glider synthesis RLE file". Retrieved on April 28, 2009.
External links
 Pentoad at the Life Lexicon
 20P5.9 at Heinrich Koenig's Game of Life Object Catalogs
Categories:
 Patterns
 Oscillators with 20 cells
 Patterns with 20 cells
 Patterns found by Bill Gosper
 Patterns found in 1977
 Patterns that can be constructed with 12 gliders
 Oscillators
 Periodic objects with minimum population 20
 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 180degree rotation symmetry
 Seminatural periodic objects