  Combinatorial classes T that are recursively defined using combinations of
the standard multiset, sequence, directed cycle and cycle constructions, and
their restrictions, have generating series T(z) with a positive radius of
convergence; for most of these a simple test can be used to quickly show that
the form of the asymptotics is the same as that for the class of rooted trees:
C \rho^{-n} n^{-3/2} where \rho is the radius of convergence of T.
