1, 2, 3, 4... are known as natural numbers.n ) then, this program displays the value of 1+2+3+....+n.#include <iostream>
using namespace std;
int main() {
int n, sum = 0;
cout << "Enter a positive integer: ";
cin >> n;
for (int i = 1; i <= n; ++i) {
sum += i;
}
cout << "Sum = " << sum;
return 0;
}Enter a positive integer: 27
Sum = 378Sum = 0 is displayed and program is terminated.