I didn't see that mentioned the number of binary trees with n nodes -- T(n) -- is precisely the Catalan numbers These can also be interpreted as the number of

I didn't see that mentioned the number of binary trees with n nodes -- T(n) -- is precisely the Catalan numbers These can also be interpreted as the number of strings of parentheses with n matching pairs So P(2) would be (()) and ()() Surely there is a bijective map between P and T somewhere in there