For several months, the broken elevener was the most common 12-cell still life without a known 5-glider synthesis, with the cheapest known recipe requiring 6 gliders. A 5-glider synthesis was found on March 1, 2023.[1][2]
x = 47, y = 48, rule = B3/S23
3bo$4bo$2b3o5$3bobo$4b2o$4bo9$40b2o$40bo$41b3o$43bo$43bob2o$44bobo7$
10b2o$9bobo$11bo3$22b3o$22bo$23bo8$bo$b2o$obo!
#C [[ THUMBSIZE 2 THEME 6 GRID GRIDMAJOR 0 SUPPRESS THUMBLAUNCH ]]
#C [[ HEIGHT 400 THEME Book ZOOM 10 AUTOSTART GPS 12 T 0 PAUSE 1 T 20 PAUSE 3 T 44 PAUSE 1 T 121 PAUSE 2 LOOP 122 ]]