How to write the following in LaTeX

[TheCanadian]

Sorry if this question is too simple or inappropriate for this forum. I just saw this text in a pdf and was wondering how I can get the specific font they used for $N$. Any ideas?

 

[Filip Larsen]

It should be possible with \mathbb{N} giving $\mathbb{N}$. See more in this old post.

 

[jtbell]

We have a newer version of that post here:

https://www.physicsforums.com/help/latexhelp/

which can also be found by scrolling down to the bottom of any page here, choosing HELP and then "Latex Primer".