Given a number N. The task is to find the sum of below series upto nth term.
3, 7, 13, 21, 31, ….
Examples:
Input : N = 3 Output : 23 Input : N = 25 Output : 5875
Approach:
Subtracting the above two equations, we have:
Below is the implementation of the above approach:
C++
// C++ Program to find the sum of given series #include <iostream> #include <math.h> using namespace std; // Function to calculate sum int findSum( int n) { // Return sum return (n * ( pow (n, 2) + 3 * n + 5)) / 3; } // Driver code int main() { int n = 25; cout << findSum(n); return 0; } |
Java
// Java program to find sum of // n terms of the given series import java.util.*; class GFG { static int calculateSum( int n) { // returning the final sum return (n * (( int )Math.pow(n, 2 ) + 3 * n + 5 )) / 3 ; } // Driver Code public static void main(String arr[]) { // number of terms to // find the sum int n = 25 ; System.out.println(calculateSum(n)); } } // This code is contributed // by Surendra_Gangwar |
Python 3
# Python program to find the # sum of given series # Function to calculate sum def findSum(n): # Return sum return (n * ( pow (n, 2 ) + 3 * n + 5 )) / 3 # driver code n = 25 print ( int (findSum(n))) |
C#
// C# program to find // sum of n terms of // the given series using System; class GFG { static int calculateSum( int n) { // returning the final sum return (n * (( int )Math.Pow(n, 2) + 3 * n + 5)) / 3; } // Driver Code public static void Main() { // number of terms to // find the sum int n = 25; Console.WriteLine(calculateSum(n)); } } // This code is contributed // by inder_verma. |
PHP
<?php // PHP Program to find the // sum of given series // Function to calculate sum function findSum( $n ) { // Return sum return ( $n * (pow( $n , 2) + 3 * $n + 5)) / 3; } // Driver code $n = 25; echo findSum( $n ); // This code is contributed // by inder_verma ?> |
Javascript
<script> // javascript program to find sum of // n terms of the given series function calculateSum(n) { // returning the final sum return (n * (parseInt(Math.pow(n, 2) + 3 * n + 5)) / 3); } // Driver Code // number of terms to // find the sum var n = 25; document.write(calculateSum(n)); // This code contributed by shikhasingrajput </script> |
5875
Time Complexity : O(1)
Auxiliary Space: O(1)
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