Given a number n, the task is to find the nth hexadecagonal number.
A Hexadecagonal number is class of figurate number and a perfect squares. It has sixteen sided polygon called hexadecagon or hexakaidecagon. The n-th hexadecagonal number count’s the sixteen number of dots and all others dots are surrounding to its successive layer.

Examples :

Input : 2
Output :16

Input :7
Output :301  ## C++

 // C++ program to find Nth  // hexadecagon number  #include  using namespace std;     // Function to calculate hexadecagonal number  int hexadecagonalNum(long int n)  {      return ((14 * n * n) - 12 * n) / 2;  }     // Drivers Code  int main()  {      long int n = 5;      cout << n << "th Hexadecagonal number : ";      cout << hexadecagonalNum(n);      cout << endl;      n = 9;      cout << n << "th Hexadecagonal number : ";      cout << hexadecagonalNum(n);         return 0;  }

## Java

 // Java program to find Nth hexadecagon  // number  import java.io.*;     class GFG {         // Function to calculate hexadecagonal      // number      static long hexadecagonalNum(long n)      {          return ((14 * n * n) - 12 * n) / 2;      }             // Drivers Code      public static void main (String[] args)      {          long n = 5;          System.out.println( n + "th "           + "Hexadecagonal number : "               + hexadecagonalNum(n));                           n = 9;          System.out.println( n + "th "           + "Hexadecagonal number : "               + hexadecagonalNum(n));      }  }     // This code contribued by anuj_67.

## Python3

 # Python program to find Nth  # hexadecagon number     # Function to calculate  # hexadecagonal number  def hexadecagonalNum(n):         # Formula to calculate nth      # Centered heptagonal number      return ((14 * n * n) - 12 * n) // 2    # Driver Code  n = 5 print("%sth Hexadecagonal number : " %n,                      hexadecagonalNum(n))  n = 9 print("%sth Hexadecagonal number : " %n,                      hexadecagonalNum(n))                         # This code is contributed by ajit

## C#

 // C# program to find Nth hexadecagon  // number  using System;  class GFG {         // Function to calculate hexadecagonal      // number      static long hexadecagonalNum(long n)      {          return ((14 * n * n) - 12 * n) / 2;      }             // Drivers Code      public static void Main ()      {          long n = 5;          Console.WriteLine( n + "th "         + "Hexadecagonal number : "             + hexadecagonalNum(n));                         n = 9;          Console.WriteLine( n + "th "         + "Hexadecagonal number : "             + hexadecagonalNum(n));      }  }     // This code contribued by anuj_67.

## PHP

 

Output :

5th Hexadecagonal number : 145


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