# Program to find Nth term of the series 3 , 5 , 21 , 51 , 95 , …

Given a number N, the task is to find the Nth term of this series:

3, 5, 21, 51, 95, ….

Examples:

```Input: N = 4
Output: 51
Explanation:
Nth term = (7 * pow(N, 2) - 19 * N + 15)
= (7 * pow(4, 2) - 19 * 4 + 15)
= 51

Input: N = 10
Output: 525
```

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

Approach:

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

``` ```

Below is the implementation of the above approach:

## C++

 `// CPP program to find N-th term of the series: ` `// 3, 5, 21, 51, 95,... ` ` `  `#include ` `#include ` `using` `namespace` `std; ` ` `  `// calculate Nth term of series ` `int` `getNthTerm(``long` `long` `int` `N) ` `{ ` `    ``// Return Nth term ` `    ``return` `(7 * ``pow``(N, 2) - 19 * N + 15); ` `} ` ` `  `// driver code ` `int` `main() ` `{ ` `    ``// declaration of number of terms ` `    ``long` `long` `int` `N = 4; ` ` `  `    ``// Get the Nth term ` `    ``cout << getNthTerm(N); ` ` `  `    ``return` `0; ` `} `

## Java

 `// Java program to find N-th term of the series: ` `// 3, 5, 21, 51, 95,... ` `import` `java.util.*; ` ` `  `class` `solution ` `{ ` `static` `long` `getNthTerm(``long` `N) ` `{ ` `// Return Nth term ` `    ``return` `(``7` `*(``int``) Math.pow(N, ``2``) - ``19` `* N + ``15``); ` `} ` ` `  `//Driver program ` `public` `static` `void` `main(String arr[]) ` `{ ` `// declaration of number of terms ` `    ``long` `N = ``4``; ` ` `  `    ``// Get the Nth term ` `     ``System.out.println(getNthTerm(N)); ` `} ` `} `

## Python3

 `# Python3 program to find N-th term  ` `# of the series: ` `# 3, 5, 21, 51, 95,... ` ` `  `# calculate Nth term of series  ` `def` `getNthTerm(N): ` `     `  `    ``#Return Nth term ` `    ``return` `(``7` `*` `pow``(N, ``2``) ``-` `19` `*` `N ``+` `15``) ` `     `  `#Driver code ` `if` `__name__``=``=``'__main__'``: ` `     `  `#declaration of number of terms ` `    ``N ``=` `4` ` `  `#Get the Nth term ` `    ``print``(getNthTerm(N)) ` ` `  `#this code is contributed by Shashank_Sharma `

## C#

 `// C# program to find  ` `// N-th term of the series: ` `// 3, 5, 21, 51, 95,... ` `using` `System; ` ` `  `class` `GFG ` `{ ` `static` `long` `getNthTerm(``long` `N) ` `{ ` `    ``// Return Nth term ` `    ``return` `(7 *(``int``) Math.Pow(N, 2) -  ` `                       ``19 * N + 15); ` `} ` ` `  `// Driver Code ` `static` `public` `void` `Main () ` `{  ` ` `  `    ``// declaration of number  ` `    ``// of terms ` `    ``long` `N = 4; ` ` `  `    ``// Get the Nth term ` `    ``Console.Write(getNthTerm(N)); ` `} ` `} ` ` `  `// This code is contributed by Raj `

## PHP

 ` `

Output:

```51
```

Time Complexity: O(1)

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