# Find Nth term of the series 5, 13, 25, 41, 61…

• Difficulty Level : Easy
• Last Updated : 15 Mar, 2021

Given a number N. The task is to write a program to find the Nth term in the below series:

`5, 13, 25, 41, 61...`

Examples:

```Input : 3
Output : 25
For N = 3
Nth term = 3*3 + (3+1)*(3+1)
= 25
Input : 5
Output : 61```

On observing carefully, the Nth term of the given series can be generalised as:

`Nth term = N2 + (N+1)2`

Below is the implementation of the above approach:

## C++

 `// CPP program to find N-th term of the series:` `// 5, 13, 25, 41, 61...` `#include ` `using` `namespace` `std;`   `// calculate Nth term of series` `int` `nthTerm(``int` `N)` `{` `    ``return` `N * N + (N + 1) * (N + 1);` `}`   `// Driver Function` `int` `main()` `{` `    ``int` `N = 3;`   `    ``cout << nthTerm(N);`   `    ``return` `0;` `}`

## Java

 `// Java program to calculate Nth term of ` `// the series: 5, 13, 25, 41, 61...`   `import` `java.io.*;`   `class` `Nth {` `    ``public` `static` `int` `nthTerm(``int` `N)` `    ``{` `        ``// By using above formula` `        ``return` `N * N + (N + ``1``) * (N + ``1``);` `    ``}` `    `  `    ``public` `static` `void` `main(String[] args)` `    ``{` `        ``int` `N = ``3``; ``// Nth term is 25` `        `  `        ``// call and print Nth term` `        ``System.out.println(nthTerm(N));` `    ``}    ` `}`

## Python 3

 `# Python 3 program to find ` `# N-th term of the series:` `# 5, 13, 25, 41, 61... `   `# Function to calculate` `# Nth term of series` `def` `nthTerm(N) :` `    ``return` `N ``*` `N ``+` `(N ``+` `1``) ``*` `(N ``+` `1``)`   `# Driver Code` `if` `__name__ ``=``=` `"__main__"` `:`   `    ``N ``=` `3`   `    ``# function calling` `    ``print``(nthTerm(N))`   `# This code is contributed ` `# by ANKITRAI1`

## C#

 `// C# program to calculate Nth term of ` `// the series: 5, 13, 25, 41, 61...` `using` `System;`   `class` `GFG ` `{` `public` `static` `int` `nthTerm(``int` `N)` `{` `    ``// By using above formula` `    ``return` `N * N + (N + 1) * (N + 1);` `}`   `// Driver Code` `public` `static` `void` `Main()` `{` `    ``int` `N = 3; ``// Nth term is 25` `    `  `    ``// call and print Nth term` `    ``Console.Write(nthTerm(N));` `} ` `}`   `// This code is contributed ` `// by ChitraNayal`

## PHP

 ``

## Javascript

 ``

Output:

`25`

Time Complexity: O(1)

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