Block on cover

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Block on cover
x = 5, y = 5, rule = B3/S23 2ob2o$2obo$3bo$3o$o! #C [[ THUMBSIZE 2 THEME 6 GRID GRIDMAJOR 0 SUPPRESS THUMBLAUNCH ]] #C [[ THUMBSIZE 3 ZOOM 21 HEIGHT 400 SUPPRESS ]] [[ ZOOM 48 ]]
Pattern type Strict still life
Number of cells 12
Bounding box 5 × 5
Frequency class 19.9
Discovered by Robert Wainwright
Everett Boyer
Year of discovery 1973

Block on cover is a 12-cell still life consisting of a block stabilizing a cover.

Commonness

Main article: List of common still lifes

Block and two tails is the fifty-sixth most common still life in Achim Flammenkamp's census, being less common than trans-bookend and bun but more common than cis-boat on dock.[1]

It is the 58th most common still life on Adam P. Goucher's Catagolue, being less common than eater head siamese eater tail but more common than cis-boat on dock. It is the 6th most common still life with 12 cells, being less common than eater head siamese eater tail but more common than cis-block on long bookend.[2]

The octo3obj database contains 22 collisions with block on cover occurring in the ash.

Construction

On April 4, 2007 Dean Hickerson found a 4-glider synthesis of this still life.[3]

A number of known alternate syntheses can be found in Mark Niemiec's database.[4]

x = 52, y = 29, rule = B3/S23 9bobo23bo$10b2o23bobo$10bo24b2o2$bo8b3o$b2o9bo21bo$obo8bo22b2o$33bobo 2$40b3o$40bo$41bo4$20bo28b2o$19b2o27b2o$bo17bobo4bo4bo18bo$2b2o22bobo 3b2o$b2o23b2o3b2o2$22bo$9bobo10bobo26bo$10b2o10b2o25b2o$10bo39b2o2$37b o9bo$38bo6b2o$36b3o7b2o! #C [[ THUMBSIZE 2 THEME 6 GRID GRIDMAJOR 0 SUPPRESS THUMBLAUNCH ]] #C [[ THEME Book ZOOM 6 AUTOSTART GPS 12 T 0 PAUSE 3 T 33 PAUSE 2 LOOP 34 ]]
Several 4G syntheses[4][5]
(click above to open LifeViewer)

See also

References

  1. Achim Flammenkamp (September 7, 2004). "Most seen natural occurring ash objects in Game of Life". Retrieved on January 15, 2009.
  2. Adam P. Goucher. "Statistics". Catagolue. Retrieved on May 5, 2023.
  3. 2, 3, and 4-glider syntheses on Dean Hickerson's Life page
  4. 4.0 4.1 The 121 twelve-bit still-lifes at Mark D. Niemiec's Life Page (download pattern file: 12/12-111.rle)
  5. carson-cheng/4g-database on GitHub

External links