Weekender

Weekender
#N Weekender #O David Eppstein #C An orthogonal period 7 spaceship with speed 2c/7. #C www.conwaylife.com/wiki/Weekender x = 16, y = 11, rule = B3/S23 bo12bo$bo12bo$obo10bobo$bo12bo$bo12bo$2bo3b4o3bo$6b4o$2b4o4b4o2$4bo6bo $5b2o2b2o! #C [[ THUMBSIZE 2 THEME 6 GRID GRIDMAJOR 0 SUPPRESS THUMBLAUNCH ]] #C [[ AUTOSTART ]] #C [[ GPS 7 TRACKLOOP 7 0 -2/7 THUMBSIZE 2 ]]
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Pattern type	Spaceship
Number of cells	36
Bounding box	18 × 12
Direction	Orthogonal
Period	7 (mod: 7)
Speed	2c/7 | 2c/7
Heat	45.1
Kinetic symmetry	Unspecified
Discovered by	David Eppstein
Year of discovery	2000
Rules Outer-totalistic rules B3/S23 – B37/S23 # of rules 21 = 2 Isotropic rules B3-ky/S23-c – B2n34cqz5ckny6-ik7/S234cekwyz5-aijq6ein7e
Glider synthesis Fewest gliders 28† Catagolue-generated RLE synthesis Uploaded synthesis RLE weekender_synth.rle †Can be constructed with 15 gliders using the reverse caber tosser universal constructor.
Pattern files Plaintext weekender.cells RLE weekender.rle
Identifiers apgcode xq7_7dfxg88gxfd7zw123u2222u321 Pentadecathlon ID 36P7H2V0.1 Eppstein ID 14105

Weekender is a 2c/7 orthogonal spaceship that was found by David Eppstein on January 12, 2000. Before the discovery of scholar in 2019, n weekenders pulling n − 1 tagalongs constituted the only known spaceships with speed 2c/7, besides self-sustaining loops of weekender conduits. These were the only known period-7 spaceships until the discovery of lobster in 2011, loafer in 2013 and spaghetti monster in 2016.

Despite the relative simplicity of its components, a glider synthesis for the weekender had been elusive since its discovery. A weekender synthesis was completed on January 25, 2015, 15 years after its discovery (and coincidentally, on a weekend). On September 26, 2015, Chris Cain announced a p444 weekender gun based on a 79-glider synthesis, as well as a p451/p457+ glider-to-weekender converter. On September 6, 2021, iNoMed produced a 33-glider recipe based on 35- and 34-glider recipes from a week earlier. A 32-glider synthesis was found in November 2023. On February 9, 2024, iNoMed reduced the synthesis to 29 gliders, followed by a reduction to 28 gliders by KtT the same day.

Tagalongs

On April 27, 2000, Stephen Silver found a tagalong for a pair of weekenders, as shown below.

x = 37, y = 24, rule = B3/S23 bo12bo7bo12bo$bo12bo7bo12bo$obo10bobo5bobo10bobo$bo12bo7bo12bo$bo12bo 7bo12bo$2bo3b4o3bo9bo3b4o3bo$6b4o8bo8b4o$2b4o4b4o2b5o2b4o4b4o$15bobobo bo$4bo6bo13bo6bo$5b2o2b2o6bobo6b2o2b2o$14bo2bobo2bo$14bo2bobo2bo$14bob o3bobo3$14b2o5b2o$14b2o5b2o2$16b2ob2o$15bobobobo$15bobobobo$17bobo$15b 2o3b2o! #C [[ THUMBSIZE 2 THEME 6 GRID GRIDMAJOR 0 SUPPRESS THUMBLAUNCH ]] #C [[ THUMBSIZE 2 ZOOM 8 ]]

Two weekenders followed by a tagalong (click above to open LifeViewer) RLE: here Plaintext: here

On December 6, 2020, John Winston Garth found doo-dah, a small period-21 tagalong for a single weekender, which in its simplest phase consists entirely of two R-pentomino descendants. The spaceship was found using a combination of ikpx2 and apgsearch, with partial results from the former being inputted into the latter via ikpx2's "standard input" feature, with the goal of searching higher-period spaceships and puffers. Garth chose the name "doo-dah" for the tagalong.

Soon after, Matthias Merzenich discovered that a component from the side of 186P7H2V0 can attach to a weekender. On March 19, 2021, Merzenich discovered a width-22 symmetric tagalong for a single weekender and proved that this is the only such period-7 symmetric tagalong at that width.

In 2024, Caleb R. Hilton found a scholar with the traffic light in front removed can act as a tagalong for a pair of scholars or weekenders.

x = 22, y = 76, rule = B3/S23 4bo12bo$4bo12bo$3bobo10bobo$4bo12bo$4bo12bo$5bo3b4o3bo$9b4o$5b4o4b4o2$ 7bo6bo$8b2o2b2o2$4bo12bo$3bob2o8b2obo$2b2ob2o8b2ob2o$2b2ob2o8b2ob2o$5b 3o6b3o$5b2o8b2o$5b2o8b2o2$6bo8bo$6b3o4b3o$5bo4b2o4bo$6b2o6b2o2$6b2o6b 2o$8b6o$4b2o2b6o2b2o$3bo2b2o6b2o2bo$4b2o10b2o$2bo2bo10bo2bo$b3ob2o2bo 2bo2b2ob3o$bobobo3bo2bo3bobobo$4b3o2bo2bo2b3o$2b3o4bo2bo4b3o$2bo6b4o6b o$4b14o$4bo2b2o4b2o2bo3$2b3obo8bob3o$3b2o2bo6bo2b2o$8bo4bo$8b2o2b2o2$ 7bo6bo$6b2o6b2o$5bo10bo$9b4o2$10b2o$8bo4bo$6b2o6b2o$4bobo8bobo$3bob3ob o2bob3obo$2b2o14b2o$2b2obo10bob2o$3b3o10b3o$4bobobo4bobobo$5b2o2bo2bo 2b2o2$3b2obo8bob2o$5b3o6b3o3$4bo12bo$2b2ob2o8b2ob2o$2bo2b2o8b2o2bo$bo 3bo10bo3bo$o5bo8bo5bo$o5bo8bo5bo$bo18bo$2bo3bo8bo3bo$3bobo10bobo$4b2o 10b2o$3b2obo8bob2o! #C [[ THUMBSIZE 2 THEME 6 GRID GRIDMAJOR 0 SUPPRESS THUMBLAUNCH ]] #C [[ HEIGHT 750 WIDTH 500 ZOOM 8 ]]

Weekender tagalong by Matthias Merzenich (click above to open LifeViewer)

x = 44, y = 86, rule = B3/S23 29bo12bo$28b3o10b3o$28b3o10b3o$b3o10b3o$o3bo8bo3bo$31bo3b2o3bo$4bo8bo 15bob4o2b4obo$o7b2o7bo11bob4o2b4obo$2b3o2bo2bo2b3o$3b2ob2o2b2ob2o3b3o 5b3o4b6o$32b2o4b2o$32b2o4b2o$5b8o5b3o5b3o$6bob2obo7bo7bo$18bo9bo$16bo 3b2o3b2o3bo$16b2ob3o3b3ob2o$15bobo11bobo$17b2ob2o3b2ob2o$20bo5bo$17b2o 9b2o$18b3o5b3o$17bo11bo$21bo3bo$13b2obo5bobo5bob2o$12bo2b4o3b3o3b4o2b o$12bo4bo2bob3obo2bo4bo$13b5obo7bob5o$15b3ob2o5b2ob3o$17b2obobobobob2o 2$17b2o3bobo3b2o$17b2o3bobo3b2o$16b2ob3o3b3ob2o$16b2o3bo3bo3b2o$16b2o 11b2o$16b2o2bo5bo2b2o$14bobob2o7b2obobo$19b2o5b2o$16bo3bo5bo3bo$14b2o b3ob2ob2ob3ob2o$15bo6bobo6bo$22bobo$22bobo$16b6o3b6o$14bo2bobo7bobo2b o$13b3o3b3o3b3o3b3o$14bo17bo$18bobo5bobo$17b2obobobobob2o$17b2obobobo bob2o$18bo2bo3bo2bo$17b2o2bo3bo2b2o$16bo4bo3bo4bo$21bo3bo$21bo3bo$20b o5bo$16bob2o7b2obo$17b4o5b4o$20bo5bo$21bo3bo$20b2o3b2o$17b2o9b2o$22bo bo$22bobo$19bo2bobo2bo2$15b2o2b2o5b2o2b2o$14bo2b2o2b5o2b2o2bo$15bo3bo 2b3o2bo3bo$15b2o2bo3bo3bo2b2o$15b2o2bo7bo2b2o$15bo2b2o7b2o2bo$16bo13b o$14bob2o11b2obo$23bo$23bo$16b3o3bobo3b3o$23bo$18b2o3bo3b2o$18b2o7b2o $18bobo5bobo$17bo11bo$16b4o7b4o$15bo15bo$15b2ob2o7b2ob2o! #C [[ THUMBSIZE 2 THEME 6 GRID GRIDMAJOR 0 SUPPRESS THUMBLAUNCH ]] #C [[ HEIGHT 750 WIDTH 500 ZOOM 8 ]]

Scholar as weekender tagalong (click above to open LifeViewer)

See also

• Weekender distaff

External links

• Searching for Spaceships - Eppstein's paper describing the discovery of the weekender
• Weekender at the Life Lexicon
• Life (B3/S23) at David Eppstein's Glider Database
• Weekender at Adam P. Goucher's Catagolue
• 36P7H2V0.1 at Heinrich Koenig's Game of Life Object Catalogs