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 <iostream> 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 |
PHP
<?php // PHP program to find N-th // term of the series: // 5, 13, 25, 41, 61... // calculate Nth term of series function nthTerm( $N )
{ return $N * $N + ( $N + 1) *
( $N + 1);
} // Driver Code $N = 3;
echo nthTerm( $N );
// This code is contributed // by ChitraNayal ?> |
Javascript
<script> // JavaScript program to find N-th term of the series: // 5, 13, 25, 41, 61... // calculate Nth term of series function nthTerm( N)
{ return N * N + (N + 1) * (N + 1);
} // Driver Function let N = 3;
document.write(nthTerm(N));
// This code contributed by Rajput-Ji </script> |
Output:
25
Time Complexity: O(1)
Space Complexity: O(1) because constant variables are used