My trees are rooted and have at most two children at every vertex. I need references that help me solve any or all of the questions below:
- How many isomorphism classes of trees with n vertices are there?
- What are the classical algorithms to decide if two given trees are isomorphic?
- Is there a nice (computable?) isomorphism invariant?
Of course, the answers may depend on the structure used to define the trees, but I guess the correct choice of structure is part of the answer I am seeking.