Perpetual motion machine?!? I'm not sure what you mean.
In theory, the principle quantum number of an electron energy level in the hydrogen atom can assume any positive integer. However, the upper limit of the energy levels is the ionization energy, which is finite. So, the levels get more and more crowded together, the higher the principle quantum number is.
I don't know what the world record is, for the greatest principle quantum number ever observed in a hydrogen atom, but I'm sure it's finite.