  The relation between the Wilson-Polchinski and the Litim optimized ERGEs in
the local potential approximation is studied with high accuracy using two
different analytical approaches based on a field expansion: a recently proposed
genuine analytical approximation scheme to two-point boundary value problems of
ordinary differential equations, and a new one based on approximating the
solution by generalized hypergeometric functions. A comparison with the
numerical results obtained with the shooting method is made. A similar accuracy
is reached in each case. Both two methods appear to be more efficient than the
usual field expansions frequently used in the current studies of ERGEs (in
particular for the Wilson-Polchinski case in the study of which they fail).
