Find Nth term of the series 4, 2, 2, 3, 6, …

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

Input:N = 2Output:2Input:N = 5Output:6

**Approach:**

- Nth number of the series is obtained by
- Multiplying the previous number with the position of the previous number itself.
- 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 <bits/stdc++.h>` `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

`<script>` ` ` `// Javascript program to find Nth term` ` ` `// of the series 4, 2, 2, 3, 6, ...` ` ` ` ` `// Function to find Nth term` ` ` `function` `nthTerm(N)` ` ` `{` ` ` `let nth = 0, first_term = 4;` ` ` `let pi = 1, po = 1;` ` ` `let n = N;` ` ` `while` `(n > 1) {` ` ` `pi *= n - 1;` ` ` `n--;` ` ` `po *= 2;` ` ` `}` ` ` `// Nth term` ` ` `nth = (first_term * pi) / po;` ` ` `return` `nth;` ` ` `}` ` ` ` ` `let N = 5;` ` ` `document.write(nthTerm(N));` `// This code is contributed by divyeshrabadiya07.` `</script>` |

**Output:**

6

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