四角形数

给定数字n，任务是找到第n个十四边形数。四边形数是称为四边形或四边形的14面多边形，属于图形数。第n个十四边形数字点有一些点，并创建了一系列图案。它们有一个共同的共享角点，并且彼此之间相互占据空间。点以第n个嵌套循环继续。

例子 ：

Input : 5
Output :125

Input :7
Output :259

第n个十四进制数的公式：-

$\begin{math} Td_{n}=((12n^2)-10n)/2 \end{math}$

C++

// Program to find nth
// Tetradecagonal number
#include 
using namespace std;
  
// Function to find
// Tetradecagonal number
int tetradecagonal_num(int n)
{
    // Formula to calculate nth
    // tetradecagonal number=
    return (12 * n * n - 10 * n) / 2;
}
  
// Driver Code
int main()
{
    int n = 2;
    cout << n << " th Tetradecagonal number: ";
    cout << tetradecagonal_num(n);
    cout << endl;
    n = 6;
    cout << n << " th Tetradecagonal number: ";
    cout << tetradecagonal_num(n);
  
    return 0;
}

Java

// Java Program to find nth
// Tetradecagonal number
import java.io.*;
  
class GFG 
{
      
// Function to find
// Tetradecagonal number
static int tetradecagonal_num(int n)
{
    // Formula to calculate nth
    // tetradecagonal number=
    return (12 * n * n - 10 * n) / 2;
}
  
// Driver Code
public static void main (String[] args) 
{
int n = 2;
System.out.print(n + " th Tetradecagonal" +
                              " number: ");
System.out.println(tetradecagonal_num(n));
  
n = 6;
System.out.print(n + " th Tetradecagonal" +
                              " number: ");
System.out.print(tetradecagonal_num(n));
  
}
}
// This code is code is
// contributed by m_kit

Python 3

# Program to find nth
# Tetradecagonal number
  
# Tetradecagonal number
# number function
def tetradecagonal_num(n) :
      
    # Formula to calculate
    # nth Tetradecagonal 
    # number return it 
    # into main function.
    return (12 * n * n - 
            10 * n) // 2
  
# Driver Code
if __name__ == '__main__' :
          
    n = 2
    print(n,"th Tetradecagonal " +
                     "number : " , 
            tetradecagonal_num(n))
  
    n = 6
    print(n,"th Tetradecagonal " +
                     "number : " , 
            tetradecagonal_num(n))
  
# This code is contributed ajit

C#

// C# Program to find nth
// Tetradecagonal number
using System;
  
class GFG
{
      
    // Function to find
    // Tetradecagonal number
    static int tetradecagonal_num(int n)
    {
          
    // Formula to calculate nth
    // tetradecagonal number
    return (12 * n * n - 
            10 * n) / 2;
    }
  
// Driver Code
static public void Main ()
{
    int n = 2;
    Console.Write(n + "th Tetradecagonal" +
                              " number: ");
    Console.WriteLine(tetradecagonal_num(n));
  
    n = 6;
    Console.Write(n + "th Tetradecagonal" +
                              " number: ");
    Console.WriteLine(tetradecagonal_num(n));
}
}
  
// This code is contributed by ajit

输出 ：

2 th Tetradecagonal number: 14
6 th Tetradecagonal number: 186

参考：
https://zh.wikipedia.org/wiki/多边形编号