Find Nth term of the series 2, 3, 10, 15, 26….
Given a number N, the task is to find the Nth term in series 2, 3, 10, 15, 26….
Example:
Input: N = 2 Output: 3 2nd term = (2*2)-1 = 3 Input: N = 5 Output: 26 5th term = (5*5)+1 = 26
Approach:
- Nth number of the series is obtained by
- Squaring the number itself.
- If the number is odd, add 1 to the squared number. And, subtract 1 if the number is even
- Since the starting number of the series is 2
1st term = 2
2nd term = (2 * 2) – 1 = 3
3rd term = (3 * 3) + 1 = 10
4th term = (4 * 4) – 1 = 15
5th term = (5 * 5) + 1 = 26
and so on….
- In general, Nth number is obtained by formula:
Below is the implementation of the above approach:
C++
// C++ program to find Nth term // of the series 2, 3, 10, 15, 26.... #include <bits/stdc++.h> using namespace std; // Function to find Nth term int nthTerm( int N) { int nth = 0; // Nth term if (N % 2 == 1) nth = (N * N) + 1; else nth = (N * N) - 1; return nth; } // Driver Method int main() { int N = 5; cout << nthTerm(N) << endl; return 0; } |
Java
// Java program to find Nth term // of the series 2, 3, 10, 15, 26.... class GFG { // Function to find Nth term static int nthTerm( int N) { int nth = 0 ; // Nth term if (N % 2 == 1 ) nth = (N * N) + 1 ; else nth = (N * N) - 1 ; return nth; } // Driver code public static void main(String[] args) { int N = 5 ; System.out.print(nthTerm(N) + "\n" ); } } // This code is contributed by Rajput-Ji |
Python3
# Python3 program to find Nth term # of the series 2, 3, 10, 15, 26.... # Function to find Nth term def nthTerm(N) : nth = 0 ; # Nth term if (N % 2 = = 1 ) : nth = (N * N) + 1 ; else : nth = (N * N) - 1 ; return nth; # Driver Method if __name__ = = "__main__" : N = 5 ; print (nthTerm(N)) ; # This code is contributed by AnkitRai01 |
C#
// C# program to find Nth term // of the series 2, 3, 10, 15, 26.... using System; class GFG { // Function to find Nth term static int nthTerm( int N) { int nth = 0; // Nth term if (N % 2 == 1) nth = (N * N) + 1; else nth = (N * N) - 1; return nth; } // Driver code public static void Main(String[] args) { int N = 5; Console.Write(nthTerm(N) + "\n" ); } } // This code is contributed by PrinciRaj1992 |
Javascript
<script> // Javascript program to find Nth term // of the series 2, 3, 10, 15, 26.... // Function to find Nth term function nthTerm(N) { let nth = 0; // Nth term if (N % 2 == 1) nth = (N * N) + 1; else nth = (N * N) - 1; return nth; } let N = 5; document.write(nthTerm(N)); // This code is contributed by divyeshrabadiya07. </script> |
Output:
26
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
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