# Centered Dodecagonal Number

Given a number n, find the** nth **Centered Dodecagonal Number.

The **Centered Dodecagonal Number** represents a dot in the center and other dots surrounding it in successive dodecagonal(12 sided polygon) layers. **Examples :**

Input : 3 Output : 37 Input : 7 Output :253

The first few centered dodecagonal numbers are:

1, 13, 37, 73, 121, 181, 253, 337, 433, 541, 661…………………..

The formula for the nth Centered dodecagonal number:

## C++

`// C++ Program to find` `// nth centered` `// Dodecagonal number` `#include <bits/stdc++.h>` `using` `namespace` `std;` `// Function to calculate Centered` `// Dodecagonal number` `int` `centeredDodecagonal(` `long` `int` `n)` `{` ` ` `// Formula to calculate nth` ` ` `// centered Dodecagonal number` ` ` `return` `6 * n * (n - 1) + 1;` `}` `// Driver Code` `int` `main()` `{` ` ` `long` `int` `n = 2;` ` ` `cout << centeredDodecagonal(n);` ` ` `cout << endl;` ` ` `n = 9;` ` ` `cout << centeredDodecagonal(n);` ` ` `return` `0;` `}` |

## Java

`// Java Program to find nth` `// centered dodecagonal number` `import` `java.io.*;` `class` `GFG{` ` ` `// Function to calculate` `// centered dodecagonal number` `static` `long` `centeredDodecagonal(` `long` `n)` `{` ` ` ` ` `// Formula to calculate nth` ` ` `// centered dodecagonal number` ` ` `return` `6` `* n * (n - ` `1` `) + ` `1` `;` `}` `// Driver Code` `public` `static` `void` `main(String[] args)` `{` ` ` `long` `n = ` `2` `;` ` ` `System.out.println(centeredDodecagonal(n));` ` ` `n = ` `9` `;` ` ` `System.out.println(centeredDodecagonal(n));` `}` `}` `// This code is contributed by anuj_67` |

## Python3

`# Python3 program to find nth` `# centered dodecagonal number` `# Function to calculate` `# centered dodecagonal number` `def` `centeredDodecagonal(n) :` ` ` ` ` `# Formula to calculate nth` ` ` `# centered dodecagonal number` ` ` `return` `6` `*` `n ` `*` `(n ` `-` `1` `) ` `+` `1` `;` `# Driver code` `n ` `=` `2` `print` `(centeredDodecagonal(n));` `n ` `=` `9` `print` `(centeredDodecagonal(n));` `# This code is contributed by grand_master` |

## C#

`// C# Program to find nth` `// centered dodecagonal number` `using` `System;` `class` `GFG{` `// Function to calculate` `// centered dodecagonal number` `static` `long` `centeredDodecagonal(` `long` `n)` `{` ` ` ` ` `// Formula to calculate nth` ` ` `// centered dodecagonal number` ` ` `return` `6 * n * (n - 1) + 1;` `}` `// Driver Code` `public` `static` `void` `Main(String[] args)` `{` ` ` `long` `n = 2;` ` ` `Console.WriteLine(centeredDodecagonal(n));` ` ` ` ` `n = 9;` ` ` `Console.WriteLine(centeredDodecagonal(n));` `}` `}` `// This code is contributed by shivanisinghss2110` |

## Javascript

`<script>` `// Javascript Program to find` `// nth centered` `// Dodecagonal number` `// Function to calculate Centered` `// Dodecagonal number` `function` `centeredDodecagonal(n)` `{` ` ` `// Formula to calculate nth` ` ` `// centered Dodecagonal number` ` ` `return` `6 * n * (n - 1) + 1;` `}` `// Driver Code` `let n = 2;` `document.write(centeredDodecagonal(n));` `document.write(` `"<br>"` `);` `n = 9;` `document.write(centeredDodecagonal(n));` `// This code is contributed by rishavmahato348.` `</script>` |

**Output :**

13 433

**Time Complexity:** O(1)**Auxiliary Space:** O(1)

References

http://oeis.org/A003154

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