In[]:=
ArrayPlot/@CellularAutomaton["GameOfLife",{CrossMatrix[1,{9,9}],0},20]
Out[]=

,
,
,
,
,
,
,
,
,
,
,
,
,
,
,
,
,
,
,
,

In[]:=
Table[GraphicsRow[SeedRandom[252424+i];(ArrayPlot/@CellularAutomaton["GameOfLife",{RandomInteger[1,{5,5}],0},20])],{i,10}]
Out[]=

,
,
,
,
,
,
,
,
,

In[]:=
Table[GraphicsRow[SeedRandom[252424+i];(ArrayPlot/@CellularAutomaton["GameOfLife",{RandomInteger[1,{5,5}],0},30])],{i,10}]
Out[]=

,
,
,
,
,
,
,
,
,

In[]:=
Table[SeedRandom[252424+i];(ArrayPlot@CellularAutomaton["GameOfLife",{RandomInteger[1,{5,5}],0},{{{200}}}]),{i,10}]
Out[]=

,
,
,
,
,
,
,
,
,


R Pentomino

First structures

16, 28