the secret "formula"

Now I would like to extend this challenge to all you math wizards out there... Is this some kind of a new formula??? That I've never had the pleasure of learning? (Actually I tried to put the horrors of math out of mind as soon as possible.) So if any one can tell me what this means you'll get... I don't know, I'll take suggestions...

Hint: this little banner hang all over the city of Barcelona
Official game rules: do not go snooping around the internet to find out what this formula means, the way to play is just to look at the formula and figure out what it could mean using only the hint above.
Thank you for playing and I'll reveal the answer next week! hehehe