catalan number calculator
#include<iostream>
using namespace std;
// A recursive function to find nth catalan number
unsigned long int catalan(unsigned int n)
{
// Base case
if (n <= 1) return 1;
// catalan(n) is sum of catalan(i)*catalan(n-i-1)
unsigned long int res = 0;
for (int i=0; i<n; i++)
res += catalan(i)*catalan(n-i-1);
return res;
}
// Driver program to test above function
int main()
{
for (int i=0; i<10; i++)
cout << catalan(i) << " ";
return 0;
}