# Find Nth term of the series 5, 13, 25, 41, 61…

• Difficulty Level : Easy
• Last Updated : 15 Mar, 2021

Given a number N. The task is to write a program to find the Nth term in the below series:

5, 13, 25, 41, 61...

Examples:

Input : 3
Output : 25
For N = 3
Nth term = 3*3 + (3+1)*(3+1)
= 25
Input : 5
Output : 61

On observing carefully, the Nth term of the given series can be generalised as:

Nth term = N2 + (N+1)2

Below is the implementation of the above approach:

## C++

 // CPP program to find N-th term of the series: // 5, 13, 25, 41, 61... #include using namespace std;   // calculate Nth term of series int nthTerm(int N) {     return N * N + (N + 1) * (N + 1); }   // Driver Function int main() {     int N = 3;       cout << nthTerm(N);       return 0; }

## Java

 // Java program to calculate Nth term of // the series: 5, 13, 25, 41, 61...   import java.io.*;   class Nth {     public static int nthTerm(int N)     {         // By using above formula         return N * N + (N + 1) * (N + 1);     }           public static void main(String[] args)     {         int N = 3; // Nth term is 25                   // call and print Nth term         System.out.println(nthTerm(N));     }    }

## Python 3

 # Python 3 program to find # N-th term of the series: # 5, 13, 25, 41, 61...   # Function to calculate # Nth term of series def nthTerm(N) :     return N * N + (N + 1) * (N + 1)   # Driver Code if __name__ == "__main__" :       N = 3       # function calling     print(nthTerm(N))   # This code is contributed # by ANKITRAI1

## C#

 // C# program to calculate Nth term of // the series: 5, 13, 25, 41, 61... using System;   class GFG { public static int nthTerm(int N) {     // By using above formula     return N * N + (N + 1) * (N + 1); }   // Driver Code public static void Main() {     int N = 3; // Nth term is 25           // call and print Nth term     Console.Write(nthTerm(N)); } }   // This code is contributed // by ChitraNayal



## Javascript



Output:

25

Time Complexity: O(1)

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