# 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

## Recommended: Please try your approach on {IDE} first, before moving on to the solution.

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  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  #include     // 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

Output:

3rd triacontagonal Number is = 87


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