# Hectagon Number

Given a number **N**, the task is to find **N ^{th}** hectagon number.

A hectagon number is class of figurate number. It has 100 – sided polygon called hectagon. The N-th hectagon number count’s the 100 number of dots and all others dots are surrounding with a common sharing corner and make a pattern. The first few hectagonol numbers are

1, 100, 297, 592 …

**Examples:**

Input:N = 2

Output:100

Explanation:

The second hectagonol number is 100.

Input:N = 3

Output:297

**Approach:** The N-th hectagon number is given by the formula:

- Nth term of s sided polygon =
- Therefore Nth term of 100 sided polygon is

Below is the implementation of the above approach:

## C++

`// C++ program for above approach ` `#include <bits/stdc++.h> ` `using` `namespace` `std; ` ` ` `// Finding the nth hectagon Number ` `int` `hectagonNum(` `int` `n) ` `{ ` ` ` `return` `(98 * n * n - 96 * n) / 2; ` `} ` ` ` `// Driver Code ` `int` `main() ` `{ ` ` ` `int` `n = 3; ` ` ` `cout << ` `"3rd hectagon Number is = "` ` ` `<< hectagonNum(n); ` ` ` ` ` `return` `0; ` `} ` ` ` `// This code is contributed by shivanisinghss2110 ` |

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## C

`// C program for above approach ` `#include <stdio.h> ` `#include <stdlib.h> ` ` ` `// Finding the nth hectagon Number ` `int` `hectagonNum(` `int` `n) ` `{ ` ` ` `return` `(98 * n * n - 96 * n) / 2; ` `} ` ` ` `// Driver program to test above function ` `int` `main() ` `{ ` ` ` `int` `n = 3; ` ` ` `printf` `(` `"3rd hectagon Number is = %d"` `, ` ` ` `hectagonNum(n)); ` ` ` ` ` `return` `0; ` `} ` |

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## Java

`// Java program for above approach ` `import` `java.util.*; ` `class` `GFG{ ` ` ` `// Finding the nth hectagon Number ` `static` `int` `hectagonNum(` `int` `n) ` `{ ` ` ` `return` `(` `98` `* n * n - ` `96` `* n) / ` `2` `; ` `} ` ` ` `// Driver Code ` `public` `static` `void` `main(String args[]) ` `{ ` ` ` `int` `n = ` `3` `; ` ` ` `System.out.print(` `"3rd hectagon Number is = "` `+ ` ` ` `hectagonNum(n)); ` `} ` `} ` ` ` `// This code is contributed by Akanksha_Rai ` |

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## Python3

`# Python3 program for above approach ` ` ` `# Finding the nth hectagon number ` `def` `hectagonNum(n): ` ` ` ` ` `return` `(` `98` `*` `n ` `*` `n ` `-` `96` `*` `n) ` `/` `/` `2` ` ` `# Driver code ` `n ` `=` `3` `print` `(` `"3rd hectagon Number is = "` `, ` ` ` `hectagonNum(n)) ` ` ` `# This code is contributed by divyamohan123 ` |

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## C#

`// C# program for above approach ` `using` `System; ` `class` `GFG{ ` ` ` `// Finding the nth hectagon Number ` `static` `int` `hectagonNum(` `int` `n) ` `{ ` ` ` `return` `(98 * n * n - 96 * n) / 2; ` `} ` ` ` `// Driver Code ` `public` `static` `void` `Main() ` `{ ` ` ` `int` `n = 3; ` ` ` `Console.Write(` `"3rd hectagon Number is = "` `+ ` ` ` `hectagonNum(n)); ` `} ` `} ` ` ` `// This code is contributed by Akanksha_Rai ` |

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**Output:**

3rd hectagon Number is = 297

**Reference:** https://en.wiktionary.org/wiki/hectagon

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