{"post":"

C++ Program to calculate the series (1) + (1+2) + (1+2+3) + (1+2+3+4) + … + (1+2+3+4+…+n)

Given: The value of n is input from user and we find the sum of the series where i-th term is sum of first i natural numbers.

Example:

Input : n = 6

Output :

1 = 1

1 + 2 = 3

1 + 2 + 3 = 6

1 + 2 + 3 + 4 = 10

1 + 2 + 3 + 4 + 5 = 15

1 + 2 + 3 + 4 + 5 + 6 = 21

The sum of the above series is : 56

# Algorithm

Take input n from the user.
Start a loop from i = 1 to i <= n.
Inside the loop, calculate the sum for the ith term by adding all the numbers from 1 to i.
After the loop, print the total sum as the result.

Code:

#include <iostream>\nusing namespace std;\n\nint main() {\n  int i, j, n, sum, total = 0;\n  cout << \"Enter the value for nth term: \";\n  cin >> n;\n  for (i = 1; i <= n; i++) {\n    sum = 0;\n    for (j = 1; j <= i; j++) {\n      total += j;\n      sum += j;\n      cout << j;\n      if (j < i) {\n        cout << \"+\";\n      }\n    }\n    cout << \" = \" << sum << endl;\n  }\n  cout << \"\\nThe sum of the above series is: \" << total << endl;\n}\n\n

Output

Enter the value for nth term: 5\n1 = 1\n1+2 = 3\n1+2+3 = 6\n1+2+3+4 = 10\n1+2+3+4+5 = 15\n\nThe sum of the above series is: 35\n\n

\n","title":"Program to calculate the series (1) + (1+2) + (1+2+3) + … + (1+2+3+4+…+n) in C++","authorDetails":{"name":"Prabhnoor Maingi","slug":"prabhnoor-maingi"},"description":"Learn how to calculate the sum of a series of terms in C++. This program uses a simple loop to add up the numbers in each term of the series and prints the result.","slug":"cpp/examples/calculate-the-series-1-12-123-1234-1234n-in-cpp/","articleId":"636a83417bb1ce5072622b45","bookmarkStatus":{"isBookmarked":false,"bookmarkId":null}}