Just one good loop

for i=1,20 do
of.setColor(10*i,0,30*i,10*i)
   of.ellipse(
      of.getWidth()/2+20*(math.cos(of.getFrameNum()/15))*i,
      of.getHeight()/2+20*(math.sin(of.getFrameNum()/100))*i,
      30+2*(math.sin(of.getFrameNum()/100))*i,
      30+2*(math.cos(of.getFrameNum()/100))*i
   )
end