A recursive C function that calculates the summation of 1 + 2 + 4 + 8 + 16 + … for a given number n

#include <bits/stdc++.h> 
using namespace std; 
  
// function to calculate sum of series 
int calculateSum(int n) 
{ 
    // initialize sum as 0 
    int sum = 0; 
  
    // loop to calculate sum of series 
    for (int i = 0; i < n; i++) { 
  
        // calculate 2^i 
        // and add it to sum 
  
        sum = sum + (1 << i); 
    } 
    return sum; 
} 
  
// Driver code 
int main() 
{ 
    int n = 10; 
    cout << "Sum of series of power of 2 is : "
         << calculateSum(n); 
}