Natural scaling for dark energy

We propose a dark energy density based on the Gauss-Bonnet 4-dimensional invariant and its modification. This model avoids the necessity of introducing the black hole limit to define the holographic density, since it can be considered as a non-saturated regime. This allows to describe the dark energy with an equation of state and Hubble parameter behaving in a way that can be adjusted very well to recent observations. The model presents quintom behavior without any future finite-time singularities.