# Program to find the Nth term of the series 3, 7, 13, 21, 31…..

Given a number N, the task is to find the Nth term of this series:

3, 7, 13, 21, 31, …….

Examples:

Input: N = 4
Output: 21
Explanation:
Nth term = (pow(N, 2) + N + 1)
= (pow(4, 2) + 4 + 1)
= 21

Input: N = 11
Output: 133


## Recommended: Please try your approach on {IDE} first, before moving on to the solution.

Approach:

Subtracting these two equations we get

Therefore, the Nth Term of the given series is:

Below is the implementation of the above approach:

 // CPP program to find the Nth term of given series.  #include  #include  using namespace std;     // Function to calculate sum  long long int getNthTerm(long long int N)  {      // Return Nth term      return (pow(N, 2) + N + 1);  }     // driver code  int main()  {      // declaration of number of terms      long long int N = 11;         // Get the Nth term      cout << getNthTerm(N);         return 0;  }

 // Java code to find the Nth term of given series.  import java.util.*;     class solution  {     // Function to calculate sum  static long getNthTerm(long N)  {            // Return Nth term      return ((int)Math.pow(N, 2) + N + 1);  }     //Driver program  public static void main(String arr[])  {            // declaration of number of terms      long N = 11;         // Get the Nth term      System.out.println(getNthTerm(N));     }  }  //THis code is contibuted by  //Surendra_Gangwar

 # Python3 Code to find the  # Nth term of given series.     # Function to calculate sum  def getNthTerm(N):             # Return Nth term      return (pow(N, 2) + N + 1)     # driver code  if __name__=='__main__':         # declaration of number of terms      N = 11        # Get the Nth term      print(getNthTerm(N))     # This code is contributed by  # Sanjit_Prasad

 // C# code to find the Nth  // term of given series.  using System;     class GFG  {     // Function to calculate sum  static long getNthTerm(long N)  {         // Return Nth term      return ((int)Math.Pow(N, 2) + N + 1);  }     // Driver Code  static public void Main ()  {             // declaration of number      // of terms      long N = 11;         // Get the Nth term      Console.Write(getNthTerm(N));  }  }     // This code is contibuted by Raj

 

Output:
133


Time Complexity: O(1)

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