# Catalan Number
- Catalan numbers are a sequence of natural numbers that helps to solve many counting problem.
- Terms starting with n=0 are : 1, 1, 2, 5, 14, 42, 132, 429, 1430 ….and so on
# Source Code - C++
#include <iostream>
using namespace std;
//Function to calculate Binomial Coefficient
int binomialC (int n, int k)
{
int ans=1;
if(k>n-k)
k=n-k;
for(int i=0; i<k; i++)
{
ans= ans*(n-i);
ans= ans/(i+1);
}
return ans;
}
//Function to calculate Catalan Number = C(2n,n)/(n+1)
void catalan(int n)
{
long int result, b;
b=binomialC(2*n,n);
result = b/(n+1);
cout<<"Catalan Number is :"<<result;
}
//Main Function
int main()
{
int n;
cout<< "enter value of n \n";
cin>>n;
catalan(n);
return 0;
}
Learn More
- Catalan Number