Given a number n, the task is to find the nth Enneadecagonal number.
An Enneadecagonal number is a nineteen-sided polygon in mathematics. It belongs to a class of figurative numbers. The number contains the number of dots and the dots are arranged in a pattern or series. An Enneadecagonal number is also known as nonadecagon. The dots have common points and all other dots are arranged in the successive layer.
Examples :
Input : 4
Output :106
Input :10
Output :775
Formula to find nth Enneadecagonal number :
C++
#include <bits/stdc++.h>
using namespace std;
int nthEnneadecagonal( long int n)
{
return (17 * n * n - 15 * n) / 2;
}
int main()
{
long int n = 6;
cout << n << "th Enneadecagonal number :" << nthEnneadecagonal(n);
return 0;
}
|
C
#include <stdio.h>
int nthEnneadecagonal( long int n)
{
return (17 * n * n - 15 * n) / 2;
}
int main()
{
long int n = 6;
printf ( "%ldth Enneadecagonal number : %d" ,n,nthEnneadecagonal(n));
return 0;
}
|
Java
import java.io.*;
class GFG {
static int nthEnneadecagonal( int n)
{
return ( 17 * n * n - 15 * n) / 2 ;
}
public static void main (String[] args)
{
int n = 6 ;
System.out.print(n + "th Enneadecagonal number :" );
System.out.println( nthEnneadecagonal(n));
}
}
|
Python3
def nthEnneadecagonal(n) :
return ( 17 * n * n - 15 * n) / / 2
if __name__ = = '__main__' :
n = 6
print (n, "th Enneadecagonal number :"
, nthEnneadecagonal(n))
|
C#
using System;
class GFG
{
static int nthEnneadecagonal( int n)
{
return (17 * n * n - 15 * n) / 2;
}
static public void Main ()
{
int n = 6;
Console.Write(n + "th Enneadecagonal number :" );
Console.WriteLine( nthEnneadecagonal(n));
}
}
|
PHP
<?php
function nthEnneadecagonal( $n )
{
return (17 * $n * $n -
15 * $n ) / 2;
}
$n = 6;
echo $n , "th Enneadecagonal number :" ,
nthEnneadecagonal( $n );
?>
|
Javascript
<script>
function nthEnneadecagonal(n)
{
return (17 * n * n - 15 * n) / 2;
}
let n = 6;
document.write(n + "th Enneadecagonal number :" );
document.write( nthEnneadecagonal(n));
</script>
|
Output:
6th Enneadecagonal number :261
Time Complexity: O(1)
Auxiliary Space: O(1)
Last Updated :
19 May, 2022
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