Given a number n, find the nth Centered Pentadecagonal Number .

A Centered Pentadecagonal Number represents a dot in the centre and other dots surrounding it in successive pentadecagonal(15-sided polygon) layers. Examples :

```Input :  2
Output : 16

Input : 8
Output : 421
```

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

n-th term of Centered pentadecagonal number:-

``` ```

Below is the basic implementation of the above idea.

## C++

 `// C++ Program to find  ` `// nth centered  ` `// pentadecagonal  number ` `#include ` `using` `namespace` `std; ` ` `  `// centered pentadecagonal function ` `int` `center_pentadecagonal_num(``long` `int` `n) ` `{ ` `    ``// Formula to calculate nth ` `    ``// centered pentadecagonal number ` `    ``return` `(15 * n * n - 15 * n + 2) / 2; ` `} ` ` `  `// Driver Code ` `int` `main() ` `{ ` `    ``long` `int` `n = 3; ` `    ``cout << n << ``"th number : "`  `             ``<< center_pentadecagonal_num(n); ` `    ``cout << endl; ` `    ``n = 10; ` `    ``cout << n << ``"th number : "` `             ``<< center_pentadecagonal_num(n); ` ` `  `    ``return` `0; ` `} `

## Java

 `// Java Program to find nth centered  ` `// pentadecagonal number ` ` `  `import` `java.io.*; ` ` `  `class` `GFG { ` `     `  `    ``// centered pentadecagonal function ` `    ``static` `long` `center_pentadecagonal_num(``long` `n) ` `    ``{ ` `     `  `        ``// Formula to calculate nth ` `        ``// centered pentadecagonal number ` `        ``return` `(``15` `* n * n - ``15` `* n + ``2``) / ``2``; ` `    ``} ` `     `  `    ``// Driver Code ` `    ``public` `static` `void` `main (String[] args)  ` `    ``{ ` `     `  `        ``long` `n = ``3``; ` `        ``System.out.print(n + ``"th number : "``); ` `        ``System.out.println(  ` `                  ``center_pentadecagonal_num(n)); ` `         `  `        ``n = ``10``; ` `        ``System.out.print( n + ``"th number : "``); ` `        ``System.out.println( ` `                 ``center_pentadecagonal_num(n)); ` `    ``} ` `} ` ` `  `// This code is contributed by ajit. `

## Python3

 `# Program to find nth ` `#centered pentadecagonal number ` ` `  `def` `center_pentadecagonal_num(n) : ` `     `  `    ``# Formula to calculate nth ` `    ``# centered pentadecagonal number ` `    ``return` `(``15` `*` `n ``*` `n ``-` `15` `*` `n ``+` `2``) ``/``/` `2` ` `  `# Driver Code ` `if` `__name__ ``=``=` `'__main__'` `: ` `         `  `    ``n ``=` `3` `    ``print``(n,``"rd number : "``, ` `                ``center_pentadecagonal_num(n)) ` `    ``n ``=` `10` `    ``print``(n,``"th number : "``, ` `                 ``center_pentadecagonal_num(n)) ` `                  `  ` `  `# This code is contributed  by m_kit `

## C#

 `// C# Program to find  ` `// nth centered  ` `// pentadecagonal number ` `using` `System; ` ` `  `class` `GFG ` `{ ` `     `  `    ``// centered  ` `    ``// pentadecagonal function ` `    ``static` `long` `center_pentadecagonal_num(``long` `n) ` `    ``{ ` `     `  `        ``// Formula to calculate  ` `        ``// nth centered  ` `        ``// pentadecagonal number ` `        ``return` `(15 * n * n - ` `                ``15 * n + 2) / 2; ` `    ``} ` `     `  `    ``// Driver Code ` `    ``static` `public` `void` `Main () ` `    ``{ ` `        ``long` `n = 3; ` `        ``Console.Write(n + ``"th number : "``); ` `        ``Console.WriteLine(  ` `                ``center_pentadecagonal_num(n)); ` `         `  `        ``n = 10; ` `        ``Console.Write( n + ``"th number : "``); ` `        ``Console.WriteLine( ` `                ``center_pentadecagonal_num(n)); ` `    ``} ` `} ` ` `  `// This code is contributed by ajit. `

## PHP

 ` `

Output :

```3th number : 46
10th number : 676
```

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