It's all in the blog post. You will have to figure out 'c' for yourself, since it changes over time. In the post I link to an R script that does it for you - you don't have to do it by hand. Look for "Navigator" in the post.

'c' changed from 300 to 200 about two years ago, but I don't know what it is now.

Edit: I think PostMixer is referring to this post on page 739.

https://bitcointalk.org/index.php?topic=1976.msg5053668#msg5053668