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

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
```

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

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

 ` `

Output:

```25
```

Time Complexity: O(1)

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Improved By : AnkitRai01, chitranayal