Question

What is Catalan numbers?

Answer 1

Answer:

Catalan numbers are a sequence of natural numbers that occurs in many interesting counting problems like following.

1) Count the number of expressions containing n pairs of parentheses which are correctly matched. For n = 3, possible expressions are ((())), ()(()), ()()(), (())(), (()()).

2) Count the number of possible Binary Search Trees with n keys

Answer 2

Answer:

"Catalan numbers are implemented in the Wolfram Language as CatalanNumber[n]. , 2, ... are 1, 2, 5, 14, 42, 132, 429, 1430, 4862, 16796, ... (OEIS A000108)."

Explanation:

hope it's helpful :)