Olympus filed patent for 14mm, 16mm, 17mm, 18mm and 22mm f/2.8 pancake lenses
Olympus filed a patent 201268448 in Japan for a whole series of f/2.8 pancake lenses: 14mm, 16mm, 17mm, 18mm and 22mm. I don't think Olympus will ever announce all of those products - manufacturers often file patents for multiple lens versions/calculations and release only one model at the end.