As I just learned, mathematics professor Andreas Weingartner from Southern Utah University, Cedar City, Utah, USA has proven the following:
lim n-> infinite Wo(n) / (0.612415 .... * x / ln x) = 1
I don't know the proof yet, but on June 30th, 2021 the proof was confirmed on
https://oeis.org/A047836.
This constant 0.612415 ... we call it the constant of the Nullwertzahlen.
Professor Andreas Weingartner has proven even more.
The following applies: Wo(n) = 0.612415... * n / ln n + O (n / (ln n )^2)
Many thanks to Professor Andreas Weingartner. This is a significant improvement on what we previously knew. So far, we have only conjectured what he has proven.