x = 27, y = 27, rule = B3678/S34678
23b2o$23b2o$25b2o$21b3ob2o$20bob2o$17bobobobo$15b6obo$15bobob3o$13b2ob
3obo$12bo5b4o$11b3o4bobo$12bo6b2o$8b5obo3bo$8bob4o2bobo$6bob10o$6b9obo
$6bobob5o$4b2o2bo2b2obo$2b4o2b7o$3b2o6bo$b2obo5b3o$bo6b2o$bobo2b4o$2o
2bo2b2o$b2o3bobo$2b5o$3bo!
A period 3 c/3 diagonal wickstretcher.
This leaves a stable wick three cells thick behind it.
David Eppstein, April 1998