  In the framework of gravitational models obtained from the Geometric
Inflation's proposal, where an infinite tower of curvature scalars are included
into the action, we compute the slow-roll parameters by the Hubble slow-roll
approach. We test the viability of such models as inflationary scenarios,
focusing on the tensor-to-scalar ratio, $r$, and spectral scalar index, $n_s$,
relation. We find that all models considered here produce inflation and, most
of them coincide, some better than others, with the marginalized 95$\%$ CL
region given by Planck's data collaboration.
