十四边形数

给定一个数 n，任务是找到第 n 个十四边形数。十四边形数是一个 14 边形的多边形，称为 tetrakaidecagon 或 tetradecagon，属于具象数。第 n 个十四边形数字点缀一些点并创建一系列图案。他们有一个共同的共享角点，并互相宠爱着自己的空间。点继续第 n 个嵌套循环。
例子 ：

Input : 5 
Output :125
Input :7 
Output :259 
 

第 n 个十四边形数的公式：-

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

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

Javascript

    // Javascript Program to find nth Tetradecagonal number
     
    // Function to find
    // Tetradecagonal number
    function tetradecagonal_num(n)
    {
           
      // Formula to calculate nth
      // tetradecagonal number
      return (12 * n * n - 10 * n) / 2;
    }
     
    let n = 2;
    document.write(n + "th Tetradecagonal number: ");
    document.write(tetradecagonal_num(n) + "</br>");
   
    n = 6;
    document.write(n + "th Tetradecagonal number: ");
    document.write(tetradecagonal_num(n));
 
// This code is contributed by suresh07.

输出 ：

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

时间复杂度： O(1)
辅助空间： O(1)

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