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6b2o$5bobo2$3bobo2$bobo$o$2o! #C [[ THUMBSIZE 2 THEME 6 GRID GRIDMAJOR 0 SUPPRESS THUMBLAUNCH ]] #C [[ AUTOSTART ]] #C [[ LOOP 2 GPS 2 THUMBSIZE 2 ]]
Pattern type Oscillator
Family Barberpole
Number of cells 11
Bounding box 8 × 8
Frequency class 38.3
Period 2
Mod 1
Heat 10
Volatility 0.63
Strict volatility 0.63
Discovered by MIT group
Year of discovery 1970

The pentapole is the barberpole of length 5. It is the eighth smallest of all oscillators, and the only non-pseudo oscillator with a minimum population of 11 cells.


The pentapole appears nowhere near as frequently as the bipole, tripole or quadpole, and is nowhere to be seen among the 88 most common oscillators in Catagolue as of February 2022. As of 13 March 2024, it is the 112th most common period-2 oscillator in Catagolue.

Much like with the tripole and other barberpoles with diagonal line symmetry, it is much more common in censuses with said symmetries; as of 13 March 2024, it is the 22nd most common period-2 oscillator in D2_x, 24th in D4_x1, 27th in D4_x4, 31st in D8_1 and 42nd in D8_4.

It first appeared naturally on March 31, 2015, in a soup submitted to Catagolue by David S. Miller.[1]

Glider synthesis

Mark Niemiec's website lists the pentapole as having a 10-glider synthesis as of 2013, using a three-glider component on an existing quadpole to lengthen it by one stage.[2] This has since been reduced to 8 gliders, based on an asymmetric seven-glider collision which produces a pentapole alongside an easily removable boat.

x = 26, y = 21, rule = B3/S23 2bo19bobo$obo19b2o$b2o20bo4$18bo$18bobo$7bo10b2o$5b2o$6b2o$20b3o$20bo$ 21bo2$5b2o$4b2o$6bo$24b2o$23b2o$25bo! #C [[ THUMBSIZE 2 THEME 6 GRID GRIDMAJOR 0 SUPPRESS THUMBLAUNCH ]] #C [[ HEIGHT 400 THEME Book ZOOM 14 AUTOSTART GPS 16 T 0 PAUSE 2 T 86 PAUSE 3 LOOP 87 ]]
Pentapole-plus-boat synthesis
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See also


  1. gameoflifeboy (April 1, 2015). Re: Soup search results (discussion thread) at the forums

External links