Siffrin's p103

siffrin's p103
x = 42, y = 42, rule = B3/S23 15bo$14bobo$15bo6$15b3o$15b2obo$15b2o2bo$16bob2o$15b3o2$bo$obo5b3obo$bo6b5o$8bo3bo$9bobo$10b2o3$30b2o$30bobo$29bo3bo$29b5o6bo$29bob3o5bobo$40bo2$24b3o$22b2obo$22bo2b2o$23bob2o$24b3o6$26bo$25bobo$26bo! #C [[ THUMBSIZE 2 THEME 6 GRID GRIDMAJOR 0 SUPPRESS THUMBLAUNCH ]] #C [[ AUTOSTART ]] #C [[ HEIGHT 560 ZOOM 12 GPS 12 ]]
View static image
Pattern type	Oscillator
Number of cells	68
Bounding box	42 × 42
Period	103 (mod: 103)
Heat	28
Volatility	0.98 | 0.98
Kinetic symmetry	xk
Discovered by	siffrin normal
Year of discovery	2026
Rules Outer-totalistic rules B3/S23 – B3/S238 # of rules 21 = 2 Isotropic rules B3/S23 – B3/S236i8
Glider synthesis Fewest gliders (canonical) 84† Catagolue-generated RLE (canonical) synthesis Fewest gliders (cheapest variant) 76† Catagolue-generated RLE (cheapest variant) synthesis †Can be constructed with 15 gliders using the reverse caber tosser universal constructor.
Pattern files Plaintext siffrinsp103.cells RLE siffrinsp103.rle
Identifiers apgcode (canonical) xp103_ya252zyboo8gz0gy957423z121y17bjq7zypgc48gzykgggw31333y1252zyi358fezymgzyl121 apgcode (cheapest variant) xp103_ya35a4zycgggzggyabf856z1252y1em6kezy711yeo8gzyq72667y14akozyj6ahvtzzym25ac Pentadecathlon ID 68P103

siffrin's p103 is a period-103 oscillator found by siffrin normal on February 21, 2026 . It consists of four copies of an unnamed active object and two tubs acting as rocks, and produces two internal unnamed sparks. With 68 cells, it is the smallest known period-103 oscillator, well below the 180-celled syringe-based loop.

Discovery

A variant with long boats instead of tubs was found in the H4_x4 symmetry (the GPU-filtered counterpart of D4_x4), shortly after GPU searching with diagonal symmetry and 90° rotations was implemented in apgsearch.

x = 32, y = 32, rule = B3/S23 bo2b5ob5o3b2ob2ob2ob2obo$o3bo2b2obobob5obobo3bob2obo$2b6o2b2o4bob2ob3o3b4o$2b4o2b2o4b3obo2b6ob4o$5o5bo3b3ob2obo5bobobo$ob2obobo3b4obob2ob2o3bobobo$obo3b2ob2o2b4o3b2o3bo2bo2bo$3o2b7obob3o3b2obo3bo2bo$2obo3b5obo2b2ob2o2bo4b2o$3bo2b3o2b3obo5bo2bobob4o$3obob3ob2obo2b2o3b2ob6obo$obo2bob7obob2obo2bobo4bo$2o3bo3bobobo9bo2b2obobo$o4b10ob3obo5b6o$2ob4o6b6ob2ob2o5bo$bob2ob2obobo2bo2b2o2bob8o$b8obo2b2o2bo2bobob2ob2obo$bo5b2ob2ob6o6b4ob2o$6o5bob3ob10o4bo$obob2o2bo9bobobo3bo3b2o$bo4bobo2bob2obob7obo2bobo$ob6ob2o3b2o2bob2ob3obob3o$4obobo2bo5bob3o2b3o2bo$2b2o4bo2b2ob2o2bob5o3bob2o$o2bo3bob2o3b3obob7o2b3o$o2bo2bo3b2o3b4o2b2ob2o3bobo$bobobo3b2ob2obob4o3bobob2obo$obobo5bob2ob3o3bo5b5o$4ob6o2bob3o4b2o2b4o$b4o3b3ob2obo4b2o2b6o$ob2obo3bobob5obobob2o2bo3bo$bob2ob2ob2ob2o3b5ob5o2bo! #C [[ THUMBSIZE 2 THEME 6 GRID GRIDMAJOR 0 SUPPRESS THUMBLAUNCH ]] #C [[ AUTOSTART GPS 12 ZOOM 10 HEIGHT 560 THUMBSIZE 2 T 0 PAUSE 1 T 152 PAUSE 1 LOOP 153 ]]

The soup from whence it emerged (click above to open LifeViewer)

Synthesis

On February 23, 2026, Chris857 found a 76-glider synthesis of the long boat version from the soup result, along with a synthesis of the tub version which Evin reduced to 84 gliders.

External links

• Siffrin's p103 at Adam P. Goucher's Catagolue

• the first discovered form (with long boats instead of tubs)