五边形数

原文:https://www.geeksforgeeks.org/pentadecagonal-number/

给定一个数 N，任务是找到第 N^{个五边形数。}

五边形数是将三角形和正方形的概念扩展到五边形(一个 15 边的多边形)的图形数。第 N ^个五边形数计算 N 个嵌套五边形图案中的点数，所有五边形共享一个公共角，其中图案中的第 i ^个三边形具有由相互间隔一个单位的“I”个点组成的边。前几个十边形数字是 1、15、42、82、135、201、280……

例:

输入: N = 2 输出: 15 说明: 第二个五边形数是 15。 输入: N = 6 输出: 201

方法:第 N 个^{五边形数由公式给出:}

以下是上述方法的实现:

C++

// C++ program to find Nth
// Pentadecagonal number
#include <bits/stdc++.h>
using namespace std;

// Function to find N-th
// Pentadecagonal number
int Pentadecagonal_num(int n)
{
    // Formula to calculate nth
    // Pentadecagonal number
    return (13 * n * n - 11 * n) / 2;
}

// Driver code
int main()
{
    int n = 3;
    cout << Pentadecagonal_num(n) << endl;

    n = 10;
    cout << Pentadecagonal_num(n) << endl;

    return 0;
}

Java 语言(一种计算机语言，尤用于创建网站)

// Java program to find Nth
// pentadecagonal number
import java.io.*;
import java.util.*;

class GFG{

// Function to find N-th
// pentadecagonal number
static int Pentadecagonal_num(int n)
{

    // Formula to calculate nth
    // Pentadecagonal number
    return (13 * n * n - 11 * n) / 2;
}

// Driver code
public static void main(String[] args)
{
    int n = 3;
    System.out.println(Pentadecagonal_num(n));

    n = 10;
    System.out.println(Pentadecagonal_num(n));
}
}

// This code is contributed by coder001

Python 3

# Python3 program to find Nth
# pentadecagonal number

# Function to find N-th
# pentadecagonal number
def Pentadecagonal_num(n):

    # Formula to calculate nth
    # pentadecagonal number
    return (13 * n * n - 11 * n) / 2

# Driver code   
n = 3
print(int(Pentadecagonal_num(n)))

n = 10
print(int(Pentadecagonal_num(n)))

# This code is contributed by divyeshrabadiya07

C

// C# program to find Nth
// pentadecagonal number
using System;
class GFG{

// Function to find N-th
// pentadecagonal number
static int Pentadecagonal_num(int n)
{

    // Formula to calculate nth
    // Pentadecagonal number
    return (13 * n * n - 11 * n) / 2;
}

// Driver code
public static void Main(string[] args)
{
    int n = 3;
    Console.Write(Pentadecagonal_num(n) + "\n");

    n = 10;
    Console.Write(Pentadecagonal_num(n) + "\n");
}
}

// This code is contributed by rutvik_56

java 描述语言

<script>

    // Javascript program to find Nth
    // Pentadecagonal number

    // Function to find N-th
    // Pentadecagonal number
    function Pentadecagonal_num(n)
    {
        // Formula to calculate nth
        // Pentadecagonal number
        return (13 * n * n - 11 * n) / 2;
    }

    let n = 3;
    document.write(Pentadecagonal_num(n) + "</br>");

    n = 10;
    document.write(Pentadecagonal_num(n));

</script>

Output: 

42
595

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

---

版权属于：月萌API www.moonapi.com，转载请注明出处

本文链接：https://moonapi.com/news/38071.html