Ok I didn't really found the love formula, but I recently have fun reading this so called Romantic Mathematics webpage which gives dozen of formulas to draw heart with mathematics only. Thanks to @codinghorror who let me discover this.
I know that it will not be a great programming challenge, but I couldn't resist to implement one of those formulas in ActionScript. It was funny to show the result to some of my coworkers last friday afternoon. One of them even asked me "And what is that intended for?" ... what a lack of romanticism! 😉