Given a number . The task is to find the N-th term in the following series:
14, 28, 20, 40, 32, 64…..
Examples:
Input : N = 5 Output : 32 Input : N = 6 Output : 64
Approach:
- Initialize first number with 14.
- Run a loop from i = 2 to N and do following steps:
- For Even i, double the previous term. For example if i = 2, current term will be 2*(term when i = 1), that is 2*14 = 28.
- For Odd i, subtract 8 from the previous term.
- Exit the loop and print the final number.
Below is the implementation of the above approach:
C++
// CPP program to find the Nth term of // the series 14, 28, 20, 40, ….. #include <iostream> using namespace std; // Function to find the N-th term int findNth( int N) { // initializing the 1st number int b = 14; int i; // loop from 2nd term to nth term for (i = 2; i <= N; i++) { // if i is even, double the // previous number if (i % 2 == 0) b = b * 2; // if i is odd, subtract 8 from // previous number else b = b - 8; } return b; } // Driver Code int main() { int N = 6; cout << findNth(N); return 0; } |
Java
// Java program to find the Nth term of // the series 14, 28, 20, 40, import java.io.*; class GFG { // Function to find the N-th term static int findNth( int N) { // initializing the 1st number int b = 14 ; int i; // loop from 2nd term to nth term for (i = 2 ; i <= N; i++) { // if i is even, double the // previous number if (i % 2 == 0 ) b = b * 2 ; // if i is odd, subtract 8 from // previous number else b = b - 8 ; } return b; } // Driver Code public static void main (String[] args) { int N = 6 ; System.out.print(findNth(N)); } } // This code is contributed by shs |
Python 3
# Python 3 program to find the Nth term # of the series 14, 28, 20, 40, ….. # Function to find the N-th term def findNth(N): # initializing the 1st number b = 14 # loop from 2nd term to nth term for i in range ( 2 , N + 1 ): # if i is even, double the # previous number if (i % 2 = = 0 ): b = b * 2 # if i is odd, subtract 8 from # previous number else : b = b - 8 return b # Driver Code N = 6 print (findNth(N)) # This code is contributed # by Akanksha Rai |
C#
// C# program to find the Nth term of // the series 14, 28, 20, 40, using System; public class GFG{ // Function to find the N-th term static int findNth( int N) { // initializing the 1st number int b = 14; int i; // loop from 2nd term to nth term for (i = 2; i <= N; i++) { // if i is even, double the // previous number if (i % 2 == 0) b = b * 2; // if i is odd, subtract 8 from // previous number else b = b - 8; } return b; } // Driver Code static public void Main (){ int N = 6; Console.WriteLine(findNth(N)); } } // This code is contributed by ajit |
PHP
<?php // PHP program to find the Nth term of // the series 14, 28, 20, 40, ….. // Function to find the N-th term function findNth( $N ) { // initializing the 1st number $b = 14; // loop from 2nd term to nth term for ( $i = 2; $i <= $N ; $i ++) { // if i is even, double the // previous number if ( $i % 2 == 0) $b = $b * 2; // if i is odd, subtract 8 from // previous number else $b = $b - 8; } return $b ; } // Driver Code $N = 6; echo findNth( $N ); // This code is contributed by akt_mit ?> |
Javascript
<script> // java script program to find the Nth term of // the series 14, 28, 20, 40, ….. // Function to find the N-th term function findNth(N) { // initializing the 1st number let b = 14; // loop from 2nd term to nth term for (let i = 2; i <= N; i++) { // if i is even, double the // previous number if (i % 2 == 0) b = b * 2; // if i is odd, subtract 8 from // previous number else b = b - 8; } return b; } // Driver Code N = 6; document.write(findNth(N)); // This code is contributed // by pulamolu mohan pavan cse </script> |
64
Time Complexity: O(N)
Auxiliary Space: O(1)
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