There is a variant with even smaller bounding box than that of Silver's. (19.12246) x = 8, y = 6, rule = B3/S23 6b2o$3b2o2bo$b3ob2o$o$b3ob2o$3bob2o! Codeholic 13:47, 6 July 2013 (UTC)
x = 8, y = 6, rule = B3/S23 6b2o$3b2o2bo$b3ob2o$o$b3ob2o$3bob2o!