Higher derivative extensions of Einstein gravity are important within the string theory approach to gravity and as alternative and effective theories of gravity.
We consider two numerical black-hole solution: by P. Kanti, et. al. in the Einstein-dilaton-Gauss-Bonnet theory [Phys.Rev. D54 (1996) 5049-5058] and
the one by H. L\"u, A. Perkins, C. Pope, K. Stelle [Phys.Rev.Lett. 114 (2015), 171601] in the Einstein gravity with added higher derivative terms. Using the general and quickly convergent parametrization in terms of the continued fractions, we represent these numerical solution in the analytical forms which are accurate not only near the event horizon or far from black hole, but in the whole space. Thereby, the obtained analytical forms of the metrics allow one to study easily all the further properties of the black holes, such as thermodynamics, Hawking radiation, particle motion, accretion, perturbations, stability, quasinormal spectrum, etc. Thus, the found analytical approximate representations can serve in the same way as exact solutions.