Related Articles
Program to find the sum of the series 1 + x + x^2+ x^3+ .. + x^n
• Last Updated : 12 Jun, 2020

Given an integer X, the task is to print the series and find the sum of the series Examples :

Input: X = 2, N = 5
Output: Sum = 31
1 2 4 8 16

Input: X = 1, N = 10
Output: Sum = 10
1 1 1 1 1 1 1 1 1 1

## Recommended: Please try your approach on {IDE} first, before moving on to the solution.

Approach: The idea is to traverse over the series and compute the sum of the N terms of the series. The Nth term of the series can be computed as:

Nth Term = (N-1)th Term * X

Below is the implementation of the above approach:

## C++

 `// C++ implementatio to find ` `// sum of series of ` `// 1 + x^2 + x^3 + ....+ x^n ` ` `  `#include ` ` `  `using` `namespace` `std; ` ` `  `// Function to find the sum of ` `// the series and print N terms ` `// of the given series ` `double` `sum(``int` `x, ``int` `n) ` `{ ` `    ``double` `i, total = 1.0, multi = x; ` ` `  `    ``// First Term ` `    ``cout << total << ``" "``; ` ` `  `    ``// Loop to print the N terms ` `    ``// of the series and find their sum ` `    ``for` `(i = 1; i < n; i++) { ` ` `  `        ``total = total + multi; ` `        ``cout << multi << ``" "``; ` `        ``multi = multi * x; ` `    ``} ` ` `  `    ``cout << ``"\n"``; ` `    ``return` `total; ` `} ` ` `  `// Driver code ` `int` `main() ` `{ ` `    ``int` `x = 2; ` `    ``int` `n = 5; ` `    ``cout << fixed ` `         ``<< setprecision(2) ` `         ``<< sum(x, n); ` `    ``return` `0; ` `} `

## C

 `// C implemenation to find the sum ` `// of series 1 + x^2 + x^3 + ....+ x^n ` ` `  `#include ` `#include ` ` `  `// Function to print the sum ` `// of the series ` `double` `sum(``int` `x, ``int` `n) ` `{ ` `    ``double` `i, total = 1.0, multi = x; ` ` `  `    ``// First Term of series ` `    ``printf``(``"1 "``); ` ` `  `    ``// Loop to find the N ` `    ``// terms of the series ` `    ``for` `(i = 1; i < n; i++) { ` ` `  `        ``total = total + multi; ` `        ``printf``(``"%.1f "``, multi); ` `        ``multi = multi * x; ` `    ``} ` `    ``printf``(``"\n"``); ` `    ``return` `total; ` `} ` ` `  `// Driver Code ` `int` `main() ` `{ ` `    ``int` `x = 2; ` `    ``int` `n = 5; ` `    ``printf``(``"%.2f"``, sum(x, n)); ` `    ``return` `0; ` `} `

## Java

 `// Java implementation to find ` `// the sum of series ` `// 1 + x^2 + x^3 + ....+ x^n ` ` `  `class` `GFG { ` ` `  `    ``// Java code to print the sum ` `    ``// of the given series ` `    ``static` `double` `sum(``int` `x, ``int` `n) ` `    ``{ ` `        ``double` `i, total = ``1.0``, multi = x; ` ` `  `        ``// First Term ` `        ``System.out.print(``"1 "``); ` ` `  `        ``// Loop to print the N terms ` `        ``// of the series and compute ` `        ``// their sum ` `        ``for` `(i = ``1``; i < n; i++) { ` `            ``total = total + multi; ` `            ``System.out.print(multi); ` `            ``System.out.print(``" "``); ` `            ``multi = multi * x; ` `        ``} ` ` `  `        ``System.out.println(); ` `        ``return` `total; ` `    ``} ` ` `  `    ``// Driver Code ` `    ``public` `static` `void` `main(String[] args) ` `    ``{ ` `        ``int` `x = ``2``; ` `        ``int` `n = ``5``; ` `        ``System.out.printf( ` `            ``"%.2f"``, sum(x, n)); ` `    ``} ` `} `

## Python3

 `# Python3 program to find sum of  ` `# series of 1 + x^2 + x^3 + ....+ x^n  ` ` `  `# Function to find the sum of  ` `# the series and print N terms  ` `# of the given series  ` `def` `sum``(x, n):  ` `     `  `    ``total ``=` `1.0` `    ``multi ``=` `x  ` ` `  `    ``# First Term  ` `    ``print``(``1``, end ``=` `" "``)  ` ` `  `    ``# Loop to print the N terms  ` `    ``# of the series and find their sum  ` `    ``for` `i ``in` `range``(``1``, n):  ` `         `  `        ``total ``=` `total ``+` `multi  ` `        ``print``(``'%.1f'` `%` `multi, end ``=` `" "``)  ` `        ``multi ``=` `multi ``*` `x  ` `         `  `    ``print``(``'\n'``) ` `    ``return` `total;  ` ` `  `# Driver code  ` `x ``=` `2` `n ``=` `5` `print``(``'%.2f'` `%` `sum``(x, n)) ` ` `  `# This code is contributed by Pratik Basu  `

## C#

 `// C# implementation to find ` `// the sum of series ` `// 1 + x^2 + x^3 + ....+ x^n ` `using` `System; ` `class` `GFG{ ` ` `  `// C# code to print the sum ` `// of the given series ` `static` `double` `sum(``int` `x, ``int` `n) ` `{ ` `    ``double` `i, total = 1.0, multi = x; ` ` `  `    ``// First Term ` `    ``Console.Write(``"1 "``); ` ` `  `    ``// Loop to print the N terms ` `    ``// of the series and compute ` `    ``// their sum ` `    ``for` `(i = 1; i < n; i++) ` `    ``{ ` `        ``total = total + multi; ` `        ``Console.Write(multi); ` `        ``Console.Write(``" "``); ` `        ``multi = multi * x; ` `    ``} ` `    ``Console.WriteLine(); ` `    ``return` `total; ` `} ` ` `  `// Driver Code ` `public` `static` `void` `Main(String[] args) ` `{ ` `    ``int` `x = 2; ` `    ``int` `n = 5; ` `    ``Console.Write(``"{0:F2}"``, sum(x, n)); ` `} ` `} ` ` `  `// This code is contributed by Rajput-Ji `

Output:

```1 2.0 4.0 8.0 16.0
31.00
```

Attention reader! Don’t stop learning now. Get hold of all the important DSA concepts with the DSA Self Paced Course at a student-friendly price and become industry ready.

My Personal Notes arrow_drop_up
Recommended Articles
Page :