#CSYNTH xs13_xca23z356 costs 4 gliders (pseudo).
#CLL state-numbering golly
x = 28, y = 20, rule = B3/S23
obo$b2o24bo$bo23b2o$26b2o9$13bo$13bobo$13b2o3$11b2o$10b2o$12bo!