Given a number N, the task is to find the Nth term of the below series:
23 + 45 + 75 + 113 + 159 +…… upto N terms
Examples:
Input: N = 4 Output: 256 Explanation: Nth term = (2 * N * (N + 1) * (4 * N + 17) + 54 * N) / 6 = (2 * 4 * (4 + 1) * (4 * 4 + 17) + 54 * 4) / 6 = 256 Input: N = 10 Output: 2180
Approach:
The Nth term of the given series can be generalized as:
Sum of first n terms of this series:
Therefore, Sum of first n terms of this series:
Below is the implementation of the above approach:
C++
// CPP program to find sum // upto N-th term of the series: // 23, 45, 75, 113... #include <iostream> using namespace std; // calculate Nth term of series int findSum( int N) { return (2 * N * (N + 1) * (4 * N + 17) + 54 * N) / 6; } // Driver Function int main() { // Get the value of N int N = 4; // Get the sum of the series cout << findSum(N) << endl; return 0; } |
Java
// Java program to find sum // upto N-th term of the series: // 23, 45, 75, 113... import java.util.*; class solution { static int findSum( int N) { //return the final sum return ( 2 * N * (N + 1 ) * ( 4 * N + 17 ) + 54 * N) / 6 ; } //Driver program public static void main(String arr[]) { // Get the value of N int N = 4 ; // Get the sum of the series System.out.println(findSum(N)); } } |
Python3
# Python3 program to find sum # upto N-th term of the series: # 23, 45, 75, 113... # calculate Nth term of series def findSum(N): return ( 2 * N * (N + 1 ) * ( 4 * N + 17 ) + 54 * N) / 6 #Driver Function if __name__ = = '__main__' : #Get the value of N N = 4 #Get the sum of the series print (findSum(N)) #this code is contributed by Shashank_Sharma |
C#
// C# program to find sum // upto N-th term of the series: // 23, 45, 75, 113... using System; class GFG { static int findSum( int N) { //return the final sum return (2 * N * (N + 1) * (4 * N + 17) + 54 * N) / 6; } // Driver Code static void Main() { // Get the value of N int N = 4; // Get the sum of the series Console.Write(findSum(N)); } } // This code is contributed by Raj |
PHP
<?php // PHP program to find sum // upto N-th term of the series: // 23, 45, 75, 113... // calculate Nth term of series function findSum( $N ) { return (2 * $N * ( $N + 1) * (4 * $N + 17) + 54 * $N ) / 6; } // Driver Code // Get the value of N $N = 4; // Get the sum of the series echo findSum( $N ); // This code is contributed // by anuj_67 ?> |
Javascript
<script> // javascript program to find sum // upto N-th term of the series: // 23, 45, 75, 113... // calculate Nth term of series function findSum( N) { return (2 * N * (N + 1) * (4 * N + 17) + 54 * N) / 6; } // Driver Function // Get the value of N let N = 4; // Get the sum of the series document.write(findSum(N)); // This code is contributed by Rajput-Ji </script> |
256
Time Complexity: O(1)
Auxiliary Space: O(1) since using constant variables
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