They also were clever when naming Fallout 76.
Fallout 1, Fallout 2, Fallout 3, Fallout New Vegas, Fallout 4, Fallout 76.
For a spin off they sure did make sure to give it a number in the title instead of something stupid like "new vegas" because bethesda specifically said they didn't want to let NV be a numbered game so it would stand out more as a spin-off lol