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Find Nth term of the series 4, 2, 2, 3, 6, …
• Last Updated : 18 Mar, 2021

Given a number N, the task is to find the N-th term in series 4, 2, 2, 3, 6, …
Example:

```Input: N = 2
Output: 2

Input: N = 5
Output: 6```

Approach:

• Nth number of the series is obtained by
1. Multiplying the previous number with the position of the previous number itself.
2. Divide the obtained number by 2.
• Since the starting number of the series is 4

```1st term = 4
2nd term = (4 * 1) / 2 = 2
3rd term = (2 * 2) / 2 = 2
4th term = (2 * 3) / 2 = 3
5th term = (3 * 4) / 2 = 6
And, so on....```
•
• In general, Nth number is obtained by formula:

•

Below is the implementation of the above approach:

## C++

 `// C++ program to find Nth term``// of the series 4, 2, 2, 3, 6, ...` `#include ``using` `namespace` `std;` `// Function to find Nth term``int` `nthTerm(``int` `N)``{``    ``int` `nth = 0, first_term = 4;` `    ``int` `pi = 1, po = 1;``    ``int` `n = N;``    ``while` `(n > 1) {``        ``pi *= n - 1;``        ``n--;``        ``po *= 2;``    ``}` `    ``// Nth term``    ``nth = (first_term * pi) / po;` `    ``return` `nth;``}` `// Driver code``int` `main()``{``    ``int` `N = 5;` `    ``cout << nthTerm(N) << endl;` `    ``return` `0;``}`

## Java

 `// Java program to find Nth term``// of the series 4, 2, 2, 3, 6, ...``class` `GFG``{` `// Function to find Nth term``static` `int` `nthTerm(``int` `N)``{``    ``int` `nth = ``0``, first_term = ``4``;` `    ``int` `pi = ``1``, po = ``1``;``    ``int` `n = N;``    ``while` `(n > ``1``)``    ``{``        ``pi *= n - ``1``;``        ``n--;``        ``po *= ``2``;``    ``}` `    ``// Nth term``    ``nth = (first_term * pi) / po;` `    ``return` `nth;``}` `// Driver code``public` `static` `void` `main(String[] args)``{``    ``int` `N = ``5``;` `    ``System.out.print(nthTerm(N) +``"\n"``);``}``}` `// This code is contributed by Rajput-Ji`

## Python3

 `# Python3 program to find Nth term``# of the series 4, 2, 2, 3, 6, ...` `# Function to find Nth term``def` `nthTerm(N) :` `    ``nth ``=` `0``; first_term ``=` `4``;` `    ``pi ``=` `1``; po ``=` `1``;``    ``n ``=` `N;``    ``while` `(n > ``1``) :``        ``pi ``*``=` `n ``-` `1``;``        ``n ``-``=` `1``;``        ``po ``*``=` `2``;` `    ``# Nth term``    ``nth ``=` `(first_term ``*` `pi) ``/``/` `po;` `    ``return` `nth;` `# Driver code``if` `__name__ ``=``=` `"__main__"` `:``    ``N ``=` `5``;``    ``print``(nthTerm(N)) ;` `# This code is contributed by AnkitRai01`

## C#

 `// C# program to find Nth term``// of the series 4, 2, 2, 3, 6, ...``using` `System;` `class` `GFG``{` `// Function to find Nth term``static` `int` `nthTerm(``int` `N)``{``    ``int` `nth = 0, first_term = 4;` `    ``int` `pi = 1, po = 1;``    ``int` `n = N;``    ``while` `(n > 1)``    ``{``        ``pi *= n - 1;``        ``n--;``        ``po *= 2;``    ``}` `    ``// Nth term``    ``nth = (first_term * pi) / po;` `    ``return` `nth;``}` `// Driver code``public` `static` `void` `Main(String[] args)``{``    ``int` `N = 5;` `    ``Console.Write(nthTerm(N) +``"\n"``);``}``}` `// This code is contributed by PrinciRaj1992`

## Javascript

 ``
Output:
`6`

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