They call this the wave equation because it is in terms of the wavelegth, whereass
E = -R(1/n2)
is called the energy equation since it is in terms of energy.
Clearly a misnomer, but very common.
It gets confusing for many students because Rydberg's constant has a different value due to the different units used. For the "energy equation" it is 2.18 x 10-18 J. Thus, due to our lack of better teaching, (or my lack of better teaching) my students often use the wrong one for the wrong equation. I have tried in previous years to use only one form of the equation and its constant to avoid confusion.
AWK
Since when is the Lymann series x-rays? From the R given, it is obious that it is for the hydrogen atom. Lymann is UV (all drops to n=1), Balmer is mostly visible (depending on whether you consider 364 UV or visible) (all falls to n=2), and Paschen is IR , etc, etc.
Calculating from n=2 to n=1 you have an energy of 984.03 kj/mol and a wavelength of 121.56 nm, clearly within the UV range and nowhere near x-rays
Valdo