The Rydberg constant is a physical constant relating to atomic spectra and it represents the limiting value of the highest wavenumber (the inverse wavelength) of any photon that can be emitted from the hydrogen atom, or, alternatively, the wavenumber of the lowest-energy photon capable of ionizing the hydrogen atom from its ground state.
The value of the Rydberg constant is
where we have
Rydberg's constant is based on the premise that the nucleus of the atom emitting light is exceedingly massive compared with a single orbiting electron (this is why the symbol for infinity,
Here's a video explaining Ryberg's formula in greater detail