Triacontagon Number
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++
// C++ program for above approach #include <bits/stdc++.h> using namespace std; // Finding the nth triacontagonal number int triacontagonalNum( int n) { return (28 * n * n - 26 * n) / 2; } // Driver code int main() { int n = 3; cout << "3rd triacontagonal Number is = " << triacontagonalNum(n); return 0; } // This code is contributed by shivanisinghss2110 |
C
// C program for above approach #include <stdio.h> #include <stdlib.h> // Finding the nth triacontagonal Number int triacontagonalNum( int n) { return (28 * n * n - 26 * n) / 2; } // Driver program to test above function int main() { int n = 3; printf ( "3rd triacontagonal Number is = %d" , triacontagonalNum(n)); return 0; } |
Java
// Java program for above approach import java.io.*; import java.util.*; class GFG { // Finding the nth triacontagonal number static int triacontagonalNum( int n) { return ( 28 * n * n - 26 * n) / 2 ; } // Driver code public static void main(String[] args) { int n = 3 ; System.out.println( "3rd triacontagonal Number is = " + triacontagonalNum(n)); } } // This code is contributed by coder001 |
Python3
# Python3 program for above approach # Finding the nth triacontagonal Number def triacontagonalNum(n): return ( 28 * n * n - 26 * n) / / 2 # Driver Code n = 3 print ( "3rd triacontagonal Number is = " , triacontagonalNum(n)) # This code is contributed by divyamohan123 |
C#
// C# program for above approach using System; class GFG{ // Finding the nth triacontagonal number static int triacontagonalNum( int n) { return (28 * n * n - 26 * n) / 2; } // Driver code public static void Main() { int n = 3; Console.Write( "3rd triacontagonal Number is = " + triacontagonalNum(n)); } } // This code is contributed by Akanksha_Rai |
Javascript
<script> // JavaScript program for above approach // Finding the nth triacontagonal number function triacontagonalNum(n) { return (28 * n * n - 26 * n) / 2; } // Driver code 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