Program to find Nth term of series 1, 3, 12, 60, 360…

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

1, 3, 12, 60, 360…

Examples:

Input: 2
Output: 3

Input: 4
Output: 60

Recommended: Please try your approach on {IDE} first, before moving on to the solution.

Approach: The idea is to first find the factorial of the number (N+1), that is (N+1)!

Now, the N-th term in the above series will be:

N-th term = (N+1)!/2

Below is the implementation of the above approach:

C++

// CPP program to find N-th term of the series: 
// 1, 3, 12, 60, 360… 
  
#include <iostream> 
using namespace std; 
  
// Function to find factorial of N 
int factorial(int N) 
{ 
    int fact = 1; 
  
    for (int i = 1; i <= N; i++) 
        fact = fact * i; 
  
    // return factorial of N+1 
    return fact; 
} 
  
// calculate Nth term of series 
int nthTerm(int N) 
{ 
    return (factorial(N + 1) / 2); 
} 
  
// Driver Function 
int main() 
{ 
  
    // Taking n as 6 
    int N = 6; 
  
    // Printing the nth term 
    cout << nthTerm(N); 
  
    return 0; 
} 

Java

// Java program to find N-th 
// term of the series: 
// 1, 3, 12, 60, 360 
  
import java.util.*; 
import java.lang.*; 
import java.io.*; 
  
class GFG { 
  
    // Function to find factorial of N 
    static int factorial(int N) 
    { 
        int fact = 1; 
  
        for (int i = 1; i <= N; i++) 
            fact = fact * i; 
  
        // return factorial of N 
        return fact; 
    } 
  
    // calculate Nth term of series 
    static int nthTerm(int N) 
    { 
        return (factorial(N + 1) / 2); 
    } 
  
    // Driver Code 
    public static void main(String args[]) 
    { 
  
        // Taking  n as 6 
        int N = 6; 
  
        // Printing the nth term 
        System.out.println(nthTerm(N)); 
    } 
} 

Python3

# Python 3 program to find  
# N-th term of the series:  
# 1, 3, 12, 60, 360…  
  
# Function for finding  
# factorial of N  
def factorial(N) :  
    fact = 1
    for i in range(1, N + 1) :  
        fact = fact * i  
  
    # return factorial of N  
    return fact  
  
# Function for calculating  
# Nth term of series  
def nthTerm(N) :  
  
    # return nth term  
    return (factorial(N + 1) // 2)  
  
# Driver code  
if __name__ == "__main__" :  
      
    N = 6
  
    # Function Calling  
    print(nthTerm(N))  

C#

// C# program to find N-th  
// term of the series:  
// 1, 3, 12, 60, 360  
using System; 
  
class GFG 
{ 
      
// Function to find factorial of N  
static int factorial(int N)  
{  
    int fact = 1;  
  
    for (int i = 1; i <= N; i++)  
        fact = fact * i;  
  
    // return factorial of N  
    return fact;  
}  
  
// calculate Nth term of series  
static int nthTerm(int N)  
{  
    return (factorial(N + 1) / 2);  
}  
  
// Driver Code 
static void Main() 
{ 
    int N = 6 ; 
      
    // Printing the nth term 
    Console.WriteLine(nthTerm(N)); 
} 
} 
  
// This code is contributed 
// by ANKITRAI1 

PHP

<?php 
// PHP program to find N-th term 
// of the series: 1, 3, 12, 60, 360… 
  
// Function to find factorial of N 
function factorial($N) 
{ 
    $fact = 1; 
  
    for ($i = 1; $i <= $N; $i++) 
        $fact = $fact * $i; 
  
    // return factorial of N+1 
    return $fact; 
} 
  
// calculate Nth term of series 
function nthTerm($N) 
{ 
    return (factorial($N + 1) / 2); 
} 
  
// Driver Code 
  
// Taking n as 6 
$N = 6; 
  
// Printing the nth term 
echo nthTerm($N); 
  
// This code is contributed  
// by chandan_jnu.. 
?> 

Output:

My Personal Notes

Recommended: Please try your approach on {IDE} first, before moving on to the solution.

C++

Java

Python3

C#

PHP

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