# Dodecagonal number

Given a number n, find the nth Dodecagonal number.Dodecagonal numbers represent Dodecagonal (A polygon with 12 sides).

Some of the Dodecagonal numbers are:

1, 12, 33, 64, 105, 156, 217, 288, 369, 460, 561, 672, 793, 924………………………..**Examples :**

Input : n = 4 Output : 64 Input : n = 9 Output : 369

**Formula of nth Term of Dodecagonal number :**

n-th Dodecagonal number = 5n^{2}- 4n

Below is the implementation for nth Dodecagonal Number:

## C++

`// CPP Program to find the` `// nth Dodecagonal number` `#include <bits/stdc++.h>` `using` `namespace` `std;` `// function for Dodecagonal` `// number` `int` `Dodecagonal_number(` `int` `n)` `{` ` ` `// formula for find Dodecagonal` ` ` `// nth term` ` ` `return` `5 * n * n - 4 * n;` `}` `// Driver Code` `int` `main()` `{` ` ` `int` `n = 7;` ` ` `cout << Dodecagonal_number(n) << endl;` ` ` `n = 12;` ` ` `cout << Dodecagonal_number(n) << endl;` ` ` `return` `0;` `}` |

## C

`// C Program to find the` `// nth Dodecagonal number` `#include <stdio.h>` `// function for Dodecagonal` `// number` `int` `Dodecagonal_number(` `int` `n)` `{` ` ` `// formula for find Dodecagonal` ` ` `// nth term` ` ` `return` `5 * n * n - 4 * n;` `}` `// Driver Code` `int` `main()` `{` ` ` `int` `n = 7;` ` ` `printf` `(` `"%d\n"` `,Dodecagonal_number(n));` ` ` `n = 12;` ` ` `printf` `(` `"%d\n"` `,Dodecagonal_number(n));` ` ` `return` `0;` `}` `// This code is contributed by kothavvsaakash` |

## Java

`// Java program to find the` `// nth Dodecagonal number` `import` `java.util.*;` `class` `GFG` `{` ` ` `// function for` ` ` `// Dodecagonal number` ` ` `static` `int` `Dodecagonal_number(` `int` `n)` ` ` `{` ` ` `// formula for find` ` ` `// Dodecagonal nth term` ` ` `return` `5` `* n * n - ` `4` `* n;` ` ` `}` ` ` ` ` `// Driver Code` ` ` `public` `static` `void` `main(String[] args)` ` ` `{` ` ` `int` `n = ` `7` `;` ` ` `System.out.println(Dodecagonal_number(n));` ` ` `n = ` `12` `;` ` ` `System.out.println(Dodecagonal_number(n));` ` ` `}` `}` `// This code is contributed by Anuj_67` |

## Python3

`# Python program to find` `# nth Dodecagonal number` `# Function to calculate` `# Dodecagonal number` `def` `Dodecagonal_number(n):` ` ` `# Formula to calculate nth` ` ` `# Dodecagonal number` ` ` ` ` `return` `5` `*` `n ` `*` `n ` `-` `4` `*` `n` `# Driver Code` `n ` `=` `7` `print` `(Dodecagonal_number(n))` `n ` `=` `12` `print` `(Dodecagonal_number(n))` ` ` `# This code is contributed by aj_36.` |

## C#

`// C# program to find the nth Dodecagonal` `// number` `using` `System;` `class` `GFG {` ` ` `// function for Dodecagonal` ` ` `// number` ` ` `static` `int` `Dodecagonal_number(` `int` `n)` ` ` `{` ` ` `// formula for find Dodecagonal` ` ` `// nth term` ` ` `return` `5 * n * n - 4 * n;` ` ` `}` ` ` ` ` `// Driver Code` ` ` `static` `void` `Main()` ` ` `{` ` ` ` ` `int` `n = 7;` ` ` `Console.WriteLine(Dodecagonal_number(n));` ` ` ` ` `n = 12;` ` ` `Console.WriteLine(Dodecagonal_number(n));` ` ` ` ` `}` `}` `// This code is contributed by Anuj_67` |

## PHP

`<?php` `// PHP Program to find the` `// nth Dodecagonal number` `// function for Dodecagonal` `// number` `function` `Dodecagonal_number(` `$n` `)` `{` ` ` ` ` `// formula for find Dodecagonal` ` ` `// nth term` ` ` `return` `5 * ` `$n` `* ` `$n` `- 4 * ` `$n` `;` `}` `// Driver code` ` ` `$n` `= 7;` ` ` `echo` `Dodecagonal_number(` `$n` `), ` `"\n"` `;` ` ` `$n` `= 12;` ` ` `echo` `Dodecagonal_number(` `$n` `), ` `"\n"` `;` ` ` `// This code is contributed by aj_36` `?>` |

## Javascript

`<script>` `// Javascript Program to find the` `// nth Dodecagonal number` `// function for Dodecagonal` `// number` `function` `Dodecagonal_number(n)` `{` ` ` `// formula for find Dodecagonal` ` ` `// nth term` ` ` `return` `5 * n * n - 4 * n;` `}` `// Driver Code` `let n = 7;` `document.write(Dodecagonal_number(n) + ` `"<br>"` `);` `n = 12;` `document.write(Dodecagonal_number(n) + ` `"<br>"` `);` `// This code is contributed by subham348.` `</script>` |

**Output :**

217 672

**Time Complexity:** O(1)**Auxiliary Space:** O(1)**References:** https://en.wikipedia.org/wiki/Dodecagonal_number