Given a positive integer N, the task is to find the Nth term of the series
0, 6, 24, 60, 120…till N terms
Examples:
Input: N = 5
Output: 120Input: N = 10
Output: 990
Approach:
From the given series, find the formula for Nth term-
1st term = 1 ^ 3 – 1 = 0
2nd term = 2 ^ 3 – 2 = 6
3rd term = 3 ^ 3 – 3 = 24
4th term = 4 ^ 3 – 4 = 60
.
.
Nth term = N ^ 3 – N
The Nth term of the given series can be generalized as-
TN = N ^ 3 – N
Illustration:
Input: N = 10
Output: 990
Explanation:
TN = N ^ 3 – N
= 10 ^ 3 – 10
= 1000 – 10
= 990
Below is the implementation of the above approach-
C++
// C++ program to implement// the above approach#include <iostream>using namespace std;// Function to return// Nth term of the seriesint nth(int n){ return n * n * n - n;}// Driver codeint main(){ int N = 5; cout << nth(N) << endl; return 0;} |
C
// C program to implement// the above approach#include <stdio.h>// Function to return// Nth term of the seriesint nth(int n){ return n * n * n - n;}// Driver codeint main(){ // Value of N int N = 5; printf("%d", nth(N)); return 0;} |
Java
// Java program to implement// the above approachimport java.io.*;class GFG { // Driver code public static void main(String[] args) { int N = 5; System.out.println(nth(N)); } // Function to return // Nth term of the series public static int nth(int n) { return n * n * n - n; }} |
Python
# Python program to implement# the above approach# Function to return# Nth term of the seriesdef nth(n): return n * n * n - n# Driver codeN = 5print(nth(N))# This code is contributed by Samim Hossain Mondal. |
C#
using System;public class GFG{ // Function to return // Nth term of the series public static int nth(int n) { return n * n * n - n; } // Driver code static public void Main() { // Code int N = 5; Console.Write(nth(N)); }}// This code is contributed by Potta Lokesh |
Javascript
<script> // JavaScript code for the above approach // Function to return // Nth term of the series function nth(n) { return n * n * n - n; } // Driver code let N = 5; document.write(nth(N) + '<br>'); // This code is contributed by Potta Lokesh </script> |
120
Time Complexity: O(1) // since no loop is used the algorithm takes up constant time to perform the operations
Auxiliary Space: O(1) // since no extra array is used so the space taken by the algorithm is constant
