# Find Nth term of the series 1, 1, 2, 6, 24…

• Difficulty Level : Medium
• Last Updated : 23 May, 2022

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

1, 1, 2, 6, 24…

Examples:

Input: 3
Output: 2
For N = 3
Nth term = (N-1)!
= 2
Input: 5
Output: 24

Nth term of the series is given by below formula:

Nth term = ( N-1)!

Below is the required implementation:

## C++

 // CPP program to find N-th term of the series:// 1, 1, 2, 6, 24...#include using namespace std; // calculate Nth term of seriesint nthTerm(int N){    if (N <= 1)        return 1;     int i, fact = 1;    for (i = 1; i < N; i++)        fact = fact * i;     return fact;} // Driver Functionint main(){    int N = 3;     cout << nthTerm(N);     return 0;}

## Java

 // Java program to find the Nth termimport java.io.*; // calculate Nth term of this series// 1, 1, 2, 6, 24...class Nth {    public int nthTerm(int N)    {        // By using above formula        if (N <= 1)            return 1;         int i, fact = 1;        for (i = 1; i < N; i++)            fact = fact * i;         return fact;    }}// Main class for main methodclass GFG {     public static void main(String[] args)    {         int N = 3;         // create object of Class Nth        Nth a = new Nth();         // call and print Nth term        System.out.println(a.nthTerm(N));    }}

## Python 3

 # Python 3 program to find# N-th term of the series:# 1, 1, 2, 6, 24... # Function to calculate# Nth term of seriesdef nthTerm(n) :     if n <= 1 :        return 1     fact = 1    for i in range(1, N) :        fact = fact * i     return fact # Driver codeif __name__ == "__main__" :     N = 3     # function calling    print(nthTerm(N)) # This code is contributed# by ANKITRAI1

## C#

 // C# program to find the// Nth term of the series// 1, 1, 2, 6, 24...using System; // calculate Nth termclass GFG{public int nthTerm(int N){    // By using above formula    if (N <= 1)        return 1;     int i, fact = 1;    for (i = 1; i < N; i++)        fact = fact * i;     return fact;} // Driver Codepublic static void Main(){    int N = 3;     // create object of Class GFG    GFG a = new GFG();     // call and print Nth term    Console.Write(a.nthTerm(N));}} // This code is contributed// by ChitraNayal



## Javascript



Output:

2

Time Complexity: O(N), where N represents the given integer.
Auxiliary Space: O(1), no extra space is required, so it is a constant.

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