Harbor

	Harbor
	<a href="/wiki/File:Harbor.png" class="image" title="Harbor image"><img alt="Harbor image" src="/w/images/f/f9/Harbor.png" decoding="async" width="153" height="153" /></a>
	<a href="/wiki/File:Harbor.png" class="image" title="Harbor image"><img alt="Harbor image" src="/w/images/f/f9/Harbor.png" decoding="async" width="153" height="153" /></a>
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Pattern type	Oscillator
Number of cells	64
Bounding box	17 × 17
Period	5 (mod: 5)
Heat	35.2
Volatility	0.64 \| 0.64
Kinetic symmetry	Unspecified
Discovered by	David Buckingham
Year of discovery	1978
Rules
Outer-totalistic rules	B3/S23 – B378/S023678
# of rules	26 = 64
Isotropic rules	B3aijnr/S23nqry – B34-einrw5-cjq6-in78/S01c234-ary5-j678
Glider synthesis
Fewest gliders	23†
Catagolue-generated RLE	synthesis
Uploaded synthesis RLE	harbor_synth.rle
	†Can be constructed with 15 gliders using the reverse caber tosser universal constructor.
Pattern files
Plaintext	harbor.cells
RLE	harbor.rle
Identifiers
apgcode	xp5_y131u0u13z3lkkk21x12kkkl3z32x12s0s21x23zy13210123
Pentadecathlon ID	64P5.5

Harbor is a period-5 oscillator that was found by David Buckingham on September 17, 1978.^[1] It was named by Dean Hickerson. In one phase, it consists of four ships and eight boats.

A 35-glider synthesis of this oscillator can be found in jslife.^[2] A 23-glider synthesis was found by yootaa on December 22, 2017.^[3] A 16-glider synthesis was found on April 22, 2023.^[4]

About 1 in 40000 odd-width eightfold symmetric soups (D8_1) form a harbor in the centre.

References

↑ Dean Hickerson's oscillator stamp collection. Retrieved on March 14, 2020.
↑ Jason Summers' jslife pattern collection. Retrieved on January 5, 2020.
↑ yootaa (December 22, 2017). Re: Synthesising Oscillators (discussion thread) at the ConwayLife.com forums
↑ shinjuku (#4159809849) (April 22, 2023). Job triggered by Adam P. Goucher at GitLab Catagolue project.