There are too many lenses with serial numbers seemingly based on lens parameters - max aperture, focal length, angle of view - for it to be a coincidence. For example:
6mm/2.8 fisheye, no 628001 - from focal length and aperture
8mm/8 fisheye, no 88011 - from focal length and aperture
7.5mm/5.6 fisheye, no 750011 - from focal length
Nikkor-N 24/2.8, no 242801 - from focal length and aperture
Nikkor-N 28/2, no 280001 - from focal length
In the 1970s many lenses had serial numbers in 1YYMM1 format or similar, where YY=year and MM=month. But there are also plenty of other lenses with serial numbers which don't seem to be based on anything. Who knows, it might be the birthday of the designer, or some other number, or just random??