#N Eater/block frob #O David Buckingham #C A period 4 oscillator found in 1976 or earlier. #C www.conwaylife.com/wiki/index.php?title=Eater/block_frob x = 10, y = 10, rule = B3/S23 b2o7b$2bo7b$2bobo5b$3bobo4b$5b2ob2o$8b2o$2b2o6b$3bo6b$3o7b$o!