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# Find nth term of series 3, 11, 31, 69, . . . . .

• Last Updated : 20 Aug, 2022

Given an integer N, the task is to find the Nth term of the series

3, 11, 31, 69, . . . . . till Nth term.

Examples:

Input: N = 3
Output: 31

Input: N = 6
Output: 223

Approach:

From the given series, find the formula for Nth term

1st term = 1 ^ 3 + (1 + 1) = 3

2nd term = 2 ^ 3 + (2 + 1) = 11

3rd term = 3 ^ 3 + (3 + 1) = 31

4th term = 4 ^ 3 + (4 + 1) = 69

.

.

Nth term = n  ^ 3 + (n + 1)

The Nth term of the given series can be generalized as-

TN = n  ^ 3 + (n + 1)

Illustration:

Input: N = 5
Output: 131
Explanation:
TN = n  ^ 3 + (n + 1)
= 5 ^ 3 + (5 + 1)
= 131

Below is the implementation of the above approach-

## C++

 `// C++ program to find nth` `// term of the series` `#include ` `using` `namespace` `std;`   `// Function to return nth` `// term of the series` `int` `find_nth_Term(``int` `n)` `{` `    ``return` `n * n * n + (n + 1);` `}`   `// Driver code` `int` `main()` `{` `    ``// Find given nth term` `    ``int` `n = 5;`   `    ``// Function call` `    ``cout << find_nth_Term(n) << endl;` `    ``return` `0;` `}`

## Java

 `// Java code for the above approach` `import` `java.io.*;`   `class` `GFG {`   `  ``// Function to return nth` `  ``// term of the series` `  ``static` `int` `find_nth_Term(``int` `n)` `  ``{` `    ``return` `n * n * n + (n + ``1``);` `  ``}`   `  ``// Driver code` `  ``public` `static` `void` `main(String[] args)` `  ``{`   `    ``// Find given nth term` `    ``int` `n = ``5``;`   `    ``// Function call` `    ``System.out.println(find_nth_Term(n));` `  ``}` `}`   `// This code is contributed by Potta Lokesh`

## Python

 `# Python program to find nth` `# term of the series`   `# Function to return nth` `# term of the series` `def` `find_nth_Term(n):` `    `  `    ``return` `n ``*` `n ``*` `n ``+` `(n ``+` `1``)`   `# Driver code`   `# Find given nth term` `n ``=` `5`   `# Function call` `print``(find_nth_Term(n))`   `# This code is contributed by Samim Hossain Mondal.`

## C#

 `// C# program to find nth` `// term of the series` `using` `System;` `class` `GFG ` `{`   `  ``// Function to return nth` `  ``// term of the series` `  ``static` `int` `find_nth_Term(``int` `n)` `  ``{` `    ``return` `n * n * n + (n + 1);` `  ``}`   `  ``// Driver code` `  ``public` `static` `int` `Main()` `  ``{`   `    ``// Find given nth term` `    ``int` `n = 5;`   `    ``// Function call` `    ``Console.WriteLine(find_nth_Term(n));` `    ``return` `0;` `  ``}` `}`   `// This code is contributed by Taranpreet`

## Javascript

 ``

Output

`131`

Time Complexity: O(1), since there is no loop or recursion.
Auxiliary Space: O(1), since no extra space has been taken.

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