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
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;
} |
C
// C program to find N-th term of the series: // 1, 3, 12, 60, 360… #include <stdio.h> // 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
printf ( "%d" ,nthTerm(N));
return 0;
} // This code is contributed by kothavvsaakash. |
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.. ?> |
Javascript
<script> // JavaScript program to find N-th term of the series: // 1, 3, 12, 60, 360… // Function to find factorial of N function factorial(N)
{ let fact = 1;
for (let i = 1; i <= N; i++)
fact = fact * i;
// return factorial of N+1
return fact;
} // calculate Nth term of series function nthTerm(N)
{ return (Math.floor(factorial(N + 1) / 2));
} // Driver Function // Taking n as 6
let N = 6;
// Printing the nth term
document.write(nthTerm(N));
// This code is contributed by Surbhi Tyagi </script> |
Output:
2520
Time Complexity: O(n), where n represents the given input.
Auxiliary Space: O(1), no extra space is required, so it is a constant.