Oooooh, I liked this one. Iterative macros ahoy!
This was a good recap of iterative macros. I enjoyed this challenge so much I extended it and then wrote a blog post about it! https://vizteriousgirl.wordpress.com/2018/04/03/prime-numbers-1/
Nice Challenge. My first iterative macro. Tricksy beasts. It's the first time where I've found that disabling Unknown field pass through is actually useful.
Tip 'o the hat to @MarqueeCrew for the idea of bracketing the starting number and searching from there