Program to find the Nth term of the series 0, 5, 14, 27, 44, ……..

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

0, 5, 14, 27, 44 …(Nth Term)

Examples:

Input: N = 4
Output: 27
For N = 4,
Nth term = ( 2 * N * N - N - 1 ) 
         = ( 2 * 4 * 4 - 4 - 1 ) 
         = 27

Input: N = 10
Output: 188

Approach: The generalized Nth term of this series: 

Nth Term: 2 * N * N - N - 1 

Below is the required implementation: 

C++

// CPP program to find N-th term of the series:
// 0, 5, 14, 27, 44 ...
#include <iostream>
#include <math.h>
using namespace std;

// Calculate Nth term of series
int nthTerm(int n)
{
    return 2 * pow(n, 2) - n - 1;
}

// Driver code
int main()
{
    int N = 4;

    cout << nthTerm(N);

    return 0;
}

Java

// Java program to find N-th term of the series:
// 0, 5, 14, 27, 44 ...
import java.util.*;

class solution
{

// Calculate Nth term of series
static int nthTerm(int n)
{
    return 2 *(int)Math.pow(n, 2) - n - 1;
}

// Driver code
public static void main(String arr[])
{
    int N = 4;

    System.out.println(nthTerm(N));
}
}
//This code is contributed by Surendra_Gangwar

Python 3

# Python 3 program to find
# N-th term of the series:
# 0, 5, 14, 27, 44 ...

# Calculate Nth term of series
def nthTerm(n):

    return 2 * pow(n, 2) - n - 1

# Driver code
if __name__ == "__main__":
    N = 4

    print(nthTerm(N))

# This code is contributed
# by ChitraNayal

C#

// C# program to find
// N-th term of the series:
// 0, 5, 14, 27, 44 ...
using System;
class GFG
{

// Calculate Nth term of series
static int nthTerm(int n)
{
    return 2 * (int)Math.Pow(n, 2) - n - 1;
}

// Driver code
static public void Main ()
{
    int N = 4;

    Console.Write(nthTerm(N));
}
}

// This code is contributed by Raj

PHP

<?php
// PHP program to find
// N-th term of the series:
// 0, 5, 14, 27, 44 ...

// Calculate Nth term of series
function nthTerm($n)
{
    return 2 * pow($n, 2) - $n - 1;
}

// Driver code
$N = 4;

echo nthTerm($N);

// This code is contributed
// by Akanksha Rai(Abby_akku)
?>

Javascript

<script>
// JavaScript program to find N-th term of the series:
// 0, 5, 14, 27, 44 ...

// Calculate Nth term of series
function nthTerm( n)
{
    return 2 * Math.pow(n, 2) - n - 1;
}

// Driver code

    let N = 4;
   document.write( nthTerm(N) );

// This code contributed by aashish1995

</script>

Output:

27

Time Complexity: O(1)

Auxiliary Space : O(1) because using constant variables

Note: Sum upto n terms of the above series(Sn) is: