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# Program to find Nth term of the series 3, 6, 18, 24, …

• Difficulty Level : Hard
• Last Updated : 10 Mar, 2021

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

`3, 6, 18, 24, 45, 54...(Nth term)`

Examples:

```Input: N = 5
Output: 45
Explanation:
For N = 5,
Nth term = ( N * ( (N/2) + ( (N%2) * 2) + N )
= ( 5 * ( (5/2) + ( (5%2) * 2) + 5 )
= ( 5 * ( 2 + ( 1 * 2) + 5 )
= 45

Input : 6
Output : 54```

Generalized Nth term of this series:

`Nth term = ( N * ( (N/2) + ((N%2) * 2) + N )`

Below is the implementation of the above approach:

## C++

 `// CPP program to find N-th term of the series:``// 3, 6, 18, 24, 45, 54...` `#include ``using` `namespace` `std;` `// function to calculate Nth term of series``int` `nthTerm(``int` `N)``{``    ``// By using above formula``    ``return` `(N * ((N / 2) + ((N % 2) * 2) + N));``}` `// Driver Function``int` `main()``{` `    ``// get the value of N``    ``int` `N = 5;` `    ``// Calculate and print the Nth term``    ``cout << ``"Nth term for N = "``         ``<< N << ``" : "``         ``<< nthTerm(N);` `    ``return` `0;``}`

## Java

 `import` `java.io.*;` `// Class to calculate Nth term of series``class` `Nth {``    ``public` `int` `nthTerm(``int` `N)``    ``{``        ``// By using above formula``        ``return` `(N * ((N / ``2``) + ((N % ``2``) * ``2``) + N));``    ``}``}` `// Main class for main method``class` `GFG {` `    ``public` `static` `void` `main(String[] args)``    ``{` `        ``// get the value of N``        ``int` `N = ``5``;` `        ``// create object of Class Nth``        ``Nth a = ``new` `Nth();` `        ``// Calculate and print the Nth term``        ``System.out.println(``"Nth term for N = "``                           ``+ N + ``" : "``                           ``+ a.nthTerm(N));``    ``}``}`

## Python3

 `# Python3 program to find N-th term of the series:``# 3, 6, 18, 24, 45, 54...`  `# function to calculate Nth term of series``def` `nthTerm( N):``    ``# By using above formula``    ``return` `(N ``*` `((N ``/``/` `2``) ``+` `((N ``%` `2``) ``*` `2``) ``+` `N))`  `# Driver Function` `# get the value of N``if` `__name__``=``=``'__main__'``:``    ``N ``=` `5` `    ``# Calculate and print the Nth term``    ``print``( ``"Nth term for N = "``, N ,``" : "``, nthTerm(N))`  `# This code is contributed by ash264`

## C#

 `// C# program to find N-th``// term of the series:``// 3, 6, 18, 24, 45, 54...``using` `System;` `class` `GFG``{``public` `int` `nthTerm(``int` `N)``{``    ``// By using above formula``    ``return` `(N * ((N / 2) +``           ``((N % 2) * 2) + N));``}` `// Driver Code``public` `static` `void` `Main()``{` `    ``// get the value of N``    ``int` `N = 5;` `    ``// create object of Class Nth``    ``GFG a = ``new` `GFG();` `    ``// Calculate and print the Nth term``    ``Console.WriteLine(``"Nth term for N = "` `+``                                ``N + ``" : "` `+``                             ``a.nthTerm(N));``}``}` `// This code is contributed``// by inder_verma..`

## PHP

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## Javascript

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Output:
`Nth term for N = 5 : 45`

Time Complexity: O(1)

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