# Icosahedral Number

Given a number n, find the n-th icosahedral number. The Icosahedral Number is class of figurative number that represents an icosahedron(a polyhedron with 20 faces) Source : Wiki).

The first few Icosahedral Numbers are 1, 12, 48, 124, 255, 456, 742, 1128, 1629…………..

Examples :

Input : 5
Output :255

Input :10
Output :2260


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

n-th term of Icosahedral Number is given by:

Basic implementation of the above idea:

## C++

 // Icosahedral number to find  // n-th term in C++  #include  using namespace std;     // Function to find  // Icosahedral number  int icosahedralnum(int n)  {      // Formula to calculate nth      // Icosahedral number &      // return it into main function.      return (n * (5 * n * n - 5 * n + 2)) / 2;  }     // Driver Code  int main()  {      int n = 7;         cout << icosahedralnum(n);      return 0;  }

## Java

 // Icosahedral number to find  // n-th term in Java  import java.io.*;     class GFG {             // Function to find      // Icosahedral number      static int icosahedralnum(int n)      {          // Formula to calculate nth          // Icosahedral number &          // return it into main function.                     return (n * (5 * n * n - 5 *                              n + 2)) / 2;      }         // Driver Code      public static void main (String[] args)       {          int n = 7;          System.out.println(                          icosahedralnum(n));      }  }     // This code is contributed by aj_36.

## Python3

 # Python 3 Program to find   # nth Icosahedral number     # Icosahedral number  # number function  def icosahedralnum(n) :             # Formula to calculate nth      # Icosahedral number      # return it into main function.      return (n * (5 * n * n -                   5 * n + 2)) // 2       # Driver Code  if __name__ == '__main__' :                 n = 7     print(icosahedralnum(n))     # This code is contributed aj_36

## C#

 // Icosahedral number to   // find n-th term in C#  using System;     class GFG  {             // Function to find      // Icosahedral number      static int icosahedralnum(int n)      {          // Formula to calculate          // nth Icosahedral number          // & return it into main           // function.          return (n * (5 * n * n -                        5 * n + 2)) / 2;      }         // Driver Code      static public void Main ()      {          int n = 7;          Console.WriteLine(icosahedralnum(n));      }  }     // This code is contributed by ajit

## PHP

 

Output

742


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