在系列1、5、32、288中找到第N个项…

给定数字n，任务是找到序列1、5、32、288中的第n个项。
例子：

Input: N = 3
Output: 32
Explanation:
3rd term = 3^3 + 2^2 + 1^1
         = 32

Input: N = 4
Output: 288
Explanation:
4th term = 4^4 + 3^3 + 2^2 + 1^1
         = 288

方法：

Nth term = n^n + (n-1)^(n-1) + (n-2)^(n-2) + ……..1^1. 
 

下面给出了上述方法的实现：

C++

// CPP code to generate  'Nth' terms
// of this sequence
 
#include 
using namespace std;
 
// Function to generate a fixed \number
int nthTerm(int N)
{
    int nth = 0, i;
 
    // Finding nth term
    for (i = N; i > 0; i--) {
 
        nth += pow(i, i);
    }
    return nth;
}
 
// Driver Method
int main()
{
    int N = 3;
    cout << nthTerm(N) << endl;
    return 0;
}

Java

// Java code to generate 'Nth' terms
// of this sequence
import java.lang.Math;
class GFG {
 
    // Function to generate a fixed \number
    public static int nthTerm(int N)
    {
        int nth = 0, i;
 
        // Finding nth term
        for (i = N; i > 0; i--) {
 
            nth += Math.pow(i, i);
        }
        return nth;
    }
 
    // Driver Method
    public static void main(String[] args)
    {
        int N = 3;
        System.out.println(nthTerm(N));
    }
}
// This code is contributed by 29AjayKumar

Python3

# Python3 code to generate 'Nth'
# terms of this sequence
 
# Function to generate a
# fixed number
def nthTerm(N):
    nth = 0
 
    # Finding nth term
    for i in range(N, 0, -1):
        nth += pow(i, i)
    return nth
 
# Driver code
N = 3
print(nthTerm(N))
 
# This code is contributed
# by Shrikant13

C#

// C# code to generate 'Nth' terms
// of this sequence
using System;
 
class GFG
{
 
    // Function to generate a fixed \number
    public static int nthTerm(int N)
    {
        int nth = 0, i;
 
        // Finding nth term
        for (i = N; i > 0; i--)
        {
            nth +=(int)Math.Pow(i, i);
        }
        return nth;
    }
 
    // Driver Method
    public static void Main()
    {
        int N = 3;
        Console.WriteLine(nthTerm(N));
    }
}
 
// This code is contributed by Code_Mech.

PHP

 0; $i--)
    {
 
        $nth += pow($i, $i);
    }
    return $nth;
}
 
// Driver Code
$N = 3;
echo(nthTerm($N));
 
// This code is contributed by Code_Mech.
?>

Javascript

// Javascript code to generate  'Nth' terms
// of this sequence
 
// Function to generate a fixed \number
function nthTerm(N)
{
    let nth = 0, i;
 
    // Finding nth term
    for (i = N; i > 0; i--)
    {
 
        nth += Math.pow(i, i);
    }
    return nth;
}
 
// Driver Method
let N = 3;
document.write(nthTerm(N));
 
// This code is contributed by subham348.

输出：

32

时间复杂度： O(N)