六边形数

给定数N ，任务是找到^第N^个六边形数。

A Hexacontagon number is class of figurate number. It has 60 – sided polygon called hexacontagon. The N-th hexacontagon number count’s the 60 number of dots and all others dots are surrounding with a common sharing corner and make a pattern. The first few hexacontagonol numbers are 1, 60, 177, 352 … 
 

例子：

Input: N = 2 
Output: 60 
Explanation: 
The second hexacontagonol number is 60. 
Input: N = 3 
Output: 177 
 

方法：第N个六对角数由下式给出：

• 侧多边形的第N个项= $\frac{((s-2)n^2 - (s-4)n)}{2}$
• 因此，60个面的多边形的第N个项是

$Tn =\frac{((60-2)n^2 - (60-4)n)}{2} =\frac{(58n^2 - 56)}{2}$

下面是上述方法的实现：

C++

// C++ program for above approach
#include 
using namespace std;
 
// Finding the nth hexacontagon number
int hexacontagonNum(int n)
{
    return (58 * n * n - 56 * n) / 2;
}
 
// Driver code
int main()
{
    int n = 3;
    cout << "3rd hexacontagon Number is = "
         << hexacontagonNum(n);
 
    return 0;
}
 
// This code is contributed by shubhamsingh10

C

// C program for above approach
#include 
#include 
 
// Finding the nth hexacontagon Number
int hexacontagonNum(int n)
{
    return (58 * n * n - 56 * n) / 2;
}
 
// Driver program to test above function
int main()
{
    int n = 3;
    printf("3rd hexacontagon Number is = %d",
           hexacontagonNum(n));
 
    return 0;
}

Java

// Java program for above approach
class GFG{
     
// Finding the nth hexacontagon number
public static int hexacontagonNum(int n)
{
    return (58 * n * n - 56 * n) / 2;
}
 
// Driver code
public static void main(String[] args)
{
    int n = 3;
    System.out.println("3rd hexacontagon Number is = " +
                                    hexacontagonNum(n));
}
}
 
// This code is contributed by divyeshrabadiya07

Python3

# Python3 program for above approach
 
# Finding the nth hexacontagon Number
def hexacontagonNum(n):
 
    return (58 * n * n - 56 * n) // 2
 
# Driver Code
n = 3
print("3rd hexacontagon Number is = ",
                  hexacontagonNum(n));
 
# This code is contributed by divyamohan123

C#

// C# program for above approach
using System;
 
class GFG{
     
// Finding the nth hexacontagon number
public static int hexacontagonNum(int n)
{
    return (58 * n * n - 56 * n) / 2;
}
 
// Driver code
public static void Main()
{
    int n = 3;
    Console.Write("3rd hexacontagon Number is = " +
                               hexacontagonNum(n));
}
}
 
// This code is contributed by Code_Mech

Javascript

 
 
// Javascript program for above approach
 
// Finding the nth hexacontagon number
function hexacontagonNum(n)
{
    return (58 * n * n - 56 * n) / 2;
}
 
// Driver code
var n = 3;
document.write("3rd hexacontagon Number is = " +hexacontagonNum(n));
 
 

输出：

3rd hexacontagon Number is = 177

参考： https ： //en.wikipedia.org/wiki/Hexacontagon