Find the Nth term in series 12, 35, 81, 173, 357, ... - GeeksforGeeks

18 Mar, 2021
Given a number N, the task is to find the Nth term in series 12, 35, 81, 173, 357, ...Example:  
Input: N = 2
Output: 35
2nd term = (12*2) + 11
         = 35

Input: N = 5
Output: 357
5th term = (12*(2^4))+11*((2^4)-1)
         = 357
 
Approach:  
Each and every number is obtained by multiplying the previous number by 2 and the addition of 11 to it.
Since starting number is 12.  
1st term = 12
2nd term = (12 * 2) / 11 = 35
3rd term = (35 * 2) / 11 = 81
4th term = (81 * 2) / 11 = 173
And, so on....
 
In general, Nth number is obtained by formula:  
 
Below is the implementation of the above approach:  
C++
Java
Python3
C#
Javascript
// C++ program to find the Nth term// in series 12, 35, 81, 173, 357, ... #include <bits/stdc++.h>using namespace std; // Function to find Nth termint nthTerm(int N){    int nth = 0, first_term = 12;     // Nth term    nth = (first_term * (pow(2, N - 1)))          + 11 * ((pow(2, N - 1)) - 1);     return nth;} // Driver Methodint main(){    int N = 5;    cout << nthTerm(N) << endl;     return 0;}
// Java program to find the Nth term// in series 12, 35, 81, 173, 357, ...class GFG{ // Function to find Nth termstatic int nthTerm(int N){    int nth = 0, first_term = 12;     // Nth term    nth = (int) ((first_term * (Math.pow(2, N - 1)))        + 11 * ((Math.pow(2, N - 1)) - 1));     return nth;} // Driver codepublic static void main(String[] args){    int N = 5;    System.out.print(nthTerm(N) +"\n");}} // This code is contributed by Rajput-Ji
# Python3 program to find the Nth term# in series 12, 35, 81, 173, 357, ... # Function to find Nth termdef nthTerm(N) :     nth = 0; first_term = 12;     # Nth term    nth = (first_term * (pow(2, N - 1))) + \            11 * ((pow(2, N - 1)) - 1);     return nth; # Driver Methodif __name__ == "__main__" :     N = 5;    print(nthTerm(N)) ; # This code is contributed by AnkitRai01
// C# program to find the Nth term// in series 12, 35, 81, 173, 357, ...using System; class GFG{ // Function to find Nth termstatic int nthTerm(int N){    int nth = 0, first_term = 12;     // Nth term    nth = (int) ((first_term * (Math.Pow(2, N - 1)))        + 11 * ((Math.Pow(2, N - 1)) - 1));     return nth;} // Driver codepublic static void Main(String[] args){    int N = 5;    Console.Write(nthTerm(N) +"\n");}} // This code is contributed by PrinciRaj1992
<script>    // Javascript program to find the Nth term    // in series 12, 35, 81, 173, 357, ...         // Function to find Nth term    function nthTerm(N)    {        let nth = 0, first_term = 12;         // Nth term        nth = (first_term * (Math.pow(2, N - 1)))              + 11 * ((Math.pow(2, N - 1)) - 1);         return nth;    }         let N = 5;    document.write(nthTerm(N)); // This code is contributed by divyeshrabadiya07.</script>
357
 
ankthon
Rajput-Ji
princiraj1992
divyeshrabadiya07
series
Mathematical
Pattern Searching
Mathematical
series
Pattern Searching
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