The nightmare of all
Conway's Life first-time players. It only stabilizes into a two-tick oscillator after
1103 ticks, leaving around it a cloud of scattered
gliders,
blinkers and
blocks. The first ones to stabilish the result were Gary Filipski and Brad Morgan, from
Case Western Reserve University. (
without computers.)
OO
OO
O
The r-pentomino is, of course, a
Methuselah.