Given a number N, the task is to find Nth Icositrigonal number or not.
An Icositrigonal number is class of figurate number. It has 23 – sided polygon called Icositrigon. The N-th Icositrigonal number count’s the 23 number of dots and all others dots are surrounding with a common sharing corner and make a pattern. The first few Icositrigonol numbers are 1, 23, 66, 130, 215, 321, 448 …
Examples:
Input: N = 2
Output: 23
Explanation:
The second Icositrigonol number is 66.
Input: N = 6
Output: 321
Approach: The N-th Icositrigonal number is given by the formula:
Below is the implementation of the above approach:
// C++ program to find nth // Icositrigonal number #include <bits/stdc++.h> using namespace std;
// Function to find N-th // Icositrigonal number int Icositrigonal_num( int n)
{ // Formula to calculate nth
// Icositrigonal number
return (21 * n * n - 19 * n) / 2;
} // Driver Code int main()
{ int n = 3;
cout << Icositrigonal_num(n) << endl;
n = 10;
cout << Icositrigonal_num(n);
return 0;
} |
// Java program to find nth // Icositrigonal number class GFG{
// Function to find N-th // Icositrigonal number static int IcositrigonalNum( int n)
{ // Formula to calculate nth
// Icositrigonal number
return ( 21 * n * n - 19 * n) / 2 ;
} // Driver code public static void main(String[] args)
{ int n = 3 ;
System.out.print(IcositrigonalNum(n) + "\n" );
n = 10 ;
System.out.print(IcositrigonalNum(n));
} } // This code is contributed by spp____ |
# Python3 program to find nth # Icositrigonal number # Function to find N-th # Icositrigonal number def IcositrigonalNum(n):
# Formula to calculate nth
# Icositrigonal number
return ( 21 * n * n - 19 * n) / 2 ;
# Driver code n = 3
print (IcositrigonalNum(n))
n = 10
print (IcositrigonalNum(n))
# This code is contributed by spp____ |
// C# program to find nth // Icositrigonal number using System;
class GFG{
// Function to find N-th // Icositrigonal number static int IcositrigonalNum( int n)
{ // Formula to calculate nth
// Icositrigonal number
return (21 * n * n - 19 * n) / 2;
} // Driver code public static void Main()
{ int n = 3;
Console.WriteLine(IcositrigonalNum(n));
n = 10;
Console.WriteLine(IcositrigonalNum(n));
} } // This code is contributed by spp____ |
<script> // Javascript program to find nth
// Icositrigonal number
// Function to find N-th
// Icositrigonal number
function Icositrigonal_num(n)
{
// Formula to calculate nth
// Icositrigonal number
return (21 * n * n - 19 * n) / 2;
}
let n = 3;
document.write(Icositrigonal_num(n) + "</br>" );
n = 10;
document.write(Icositrigonal_num(n));
</script> |
Output:
66 955
Reference: https://en.wikipedia.org/wiki/Polygonal_number