Icosikaioctagon or Icosioctagon Number
Last Updated :
23 Jun, 2021
Given a number N, the task is to find Nth Icosioctagon number.
An Icosioctagon number is class of figurate number. It has 28 – sided polygon called icosikaioctagon. The N-th icosikaioctagonal number count’s the 28 number of dots and all others dots are surrounding with a common sharing corner and make a pattern. The first few icosikaioctagonol numbers are 1, 28, 81, 160 …
Examples:
Input: N = 2
Output: 28
Explanation:
The second icosikaioctagonol number is 28.
Input: N = 3
Output: 81
Approach: The N-th icosikaioctagonal number is given by the formula:
- Nth term of s sided polygon =
- Therefore Nth term of 28 sided polygon is
Below is the implementation of the above approach:
C++
#include <iostream>
using namespace std;
int icosikaioctagonalNum( int n)
{
return (26 * n * n - 24 * n) / 2;
}
int main()
{
int n = 3;
cout << "3rd icosikaioctagonal Number is = "
<< icosikaioctagonalNum(n);
return 0;
}
|
C
#include <stdio.h>
#include <stdlib.h>
int icosikaioctagonalNum( int n)
{
return (26 * n * n - 24 * n) / 2;
}
int main()
{
int n = 3;
printf ( "3rd icosikaioctagonal Number is = %d" ,
icosikaioctagonalNum(n));
return 0;
}
|
Java
class GFG{
public static int icosikaioctagonalNum( int n)
{
return ( 26 * n * n - 24 * n) / 2 ;
}
public static void main(String[] args)
{
int n = 3 ;
System.out.println( "3rd icosikaioctagonal Number is = " +
icosikaioctagonalNum(n));
}
}
|
Python3
def icosikaioctagonalNum(n):
return ( 26 * n * n - 24 * n) / / 2
n = 3
print ( "3rd icosikaioctagonal Number is = " ,
icosikaioctagonalNum(n))
|
C#
using System;
class GFG{
public static int icosikaioctagonalNum( int n)
{
return (26 * n * n - 24 * n) / 2;
}
public static void Main()
{
int n = 3;
Console.Write( "3rd icosikaioctagonal Number is = " +
icosikaioctagonalNum(n));
}
}
|
Javascript
<script>
function icosikaioctagonalNum(n)
{
return (26 * n * n - 24 * n) / 2;
}
var n = 3;
document.write( "3rd icosikaioctagonal Number is = " + icosikaioctagonalNum(n));
</script>
|
Output: 3rd icosikaioctagonal Number is = 81
Time Complexity: O(1)
Auxiliary Space: O(1)
Reference: https://en.wikipedia.org/wiki/Icosioctagon
Like Article
Suggest improvement
Share your thoughts in the comments
Please Login to comment...