How to get F# syntax highlighting?

Pandoc uses the syntax definitions from KDE's Kate editor. F# is included in that list. In fact, if you run pandoc --list-highlight-languages, you'll find cs (for C#) and fsharp (for F#). Not sure how that inconsitency came to be.

So it should be sufficient to start your code blocks with ``` fsharp to get proper highlighting. You may have to update pandoc to make sure fsharp support is included.

If you'd rather use minted than pandoc's built-in highlighter, checkout the minted pandoc Lua filter.