Given a number N, the task is to find Nth Triacontagon number.
An Triacontagon number is class of figurate number. It has 30 – sided polygon called triacontagon. The N-th triacontagonal number count’s the 30 number of dots and all others dots are surrounding with a common sharing corner and make a pattern. The first few triacontagonol numbers are 1, 30, 87, 172 …
Examples:
Input: N = 2
Output: 30
Explanation:
The second triacontagonol number is 30.
Input: N = 3
Output: 87
Approach: The N-th triacontagonal number is given by the formula:
- Nth term of s sided polygon =
- Therefore Nth term of 30 sided polygon is
Below is the implementation of the above approach:
C++
#include <bits/stdc++.h>
using namespace std;
int triacontagonalNum( int n)
{
return (28 * n * n - 26 * n) / 2;
}
int main()
{
int n = 3;
cout << "3rd triacontagonal Number is = "
<< triacontagonalNum(n);
return 0;
}
|
C
#include <stdio.h>
#include <stdlib.h>
int triacontagonalNum( int n)
{
return (28 * n * n - 26 * n) / 2;
}
int main()
{
int n = 3;
printf ( "3rd triacontagonal Number is = %d" ,
triacontagonalNum(n));
return 0;
}
|
Java
import java.io.*;
import java.util.*;
class GFG {
static int triacontagonalNum( int n)
{
return ( 28 * n * n - 26 * n) / 2 ;
}
public static void main(String[] args)
{
int n = 3 ;
System.out.println( "3rd triacontagonal Number is = " +
triacontagonalNum(n));
}
}
|
Python3
def triacontagonalNum(n):
return ( 28 * n * n - 26 * n) / / 2
n = 3
print ( "3rd triacontagonal Number is = " ,
triacontagonalNum(n))
|
C#
using System;
class GFG{
static int triacontagonalNum( int n)
{
return (28 * n * n - 26 * n) / 2;
}
public static void Main()
{
int n = 3;
Console.Write( "3rd triacontagonal Number is = " +
triacontagonalNum(n));
}
}
|
Javascript
<script>
function triacontagonalNum(n)
{
return (28 * n * n - 26 * n) / 2;
}
var n = 3;
document.write( "3rd triacontagonal Number is = " + triacontagonalNum(n));
</script>
|
Output: 3rd triacontagonal Number is = 87
Time Complexity: O(1)
Auxiliary Space: O(1)
Reference: https://en.wikipedia.org/wiki/Triacontagon
Last Updated :
23 Jun, 2021
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