Q:

# Write a program in C++ to calculate the series (1) + (1+2) + (1+2+3) + (1+2+3+4) + ... + (1+2+3+4+...+n)

Write a program in C++ to calculate the series (1) + (1+2) + (1+2+3) + (1+2+3+4) + ... + (1+2+3+4+...+n)

Sample Output:

``` Find the sum of the series (1) + (1+2) + (1+2+3) + (1+2+3+4) + ... + (
1+2+3+4+...+n):
-----------------------------------------------------------------------
-------------------
Input the value for nth term: 5
1 = 1
1+2 = 3
1+2+3 = 6
1+2+3+4 = 10
1+2+3+4+5 = 15
The sum of the above series is: 35
```

``````#include <iostream>
using namespace std;

int main()
{
int i, j, n, sum = 0, tsum;
cout << "\n\n Find the sum of the series (1) + (1+2) + (1+2+3) + (1+2+3+4) + ... + (1+2+3+4+...+n):\n";
cout << "------------------------------------------------------------------------------------------\n";
cout << " Input the value for nth term: ";
cin >> n;
for (i = 1; i <= n; i++)
{
tsum = 0;
for (j = 1; j <= i; j++)
{
sum += j;
tsum += j;
cout << j;
if (j < i)
{
cout << "+";
}
}
cout << " = " << tsum << endl;
}
cout << " The sum of the above series is: " << sum << endl;
}``````