1.

Specific Destiel Fic

This was a smart Dean fic where Dean accidentally solves an unsolvable math problem. I know it is destiel. I think it was at AO3.

2.

General Smart Dean fics with some restriction.

Also if there are any more like this one. I really would like some smart Dean. No wincest not hint or even implications of it. Gen, destiel, and OC are okay woth me but no wincest please. Please tell me if it's a one shot or a long story. THANK YOU SO MUCH FOR YOUR HELP!

From the top of my head I've already read the Cazadore series by Enola Jones