Let \( f : (0,\infty) \to \mathbb{R} \) and \(\displaystyle F(x) = \int_{0}^{x} t\,f(t)\,dt \). If \( F(x^{2}) = x^{4} + x^{5} \), then \(\displaystyle \sum_{r=1}^{12} f(r^{2}) \) is equal to ________.