Decakismyriagon Number

Given a number N, the task is to find N^th Decakismyriagon Number.

A Decakismyriagon Number is a class of figurate numbers. It has a 100000-sided polygon called Decakismyriagon. The N-th Decakismyriagon Number counts the 100000 number of dots and all other dots are surrounding with a common sharing corner and make a pattern. The first few Decakismyriagonol Numbers are 1, 100000, 299997, 599992, …

Examples:

Input: N = 2 
Output: 100000 
Explanation:
The second Decakismyriagonol number is 100000. 
Input: N = 3 
Output: 299997 

Approach: The N-th Decakismyriagon Number is given by the formula: 

• N-th term of S sided polygon = 
• Therefore, the N-th term of 100000 sided polygon is given by: 
  

• 
  

Below is the implementation of the above approach:

C/C++

C++

// C++ program for the above approach
#include <bits/stdc++.h>
using namespace std;

// Function to find the N-th
// Decakismyriagon Number
int DecakismyriagonNum(int N)
{
    return (99998 * N * N - 99996 * N)
        / 2;
}

// Driver Code
int main()
{
    // Given Number N
    int N = 3;

    // Function Call
    cout << DecakismyriagonNum(N);

    return 0;
}

Java

// Java program for the above approach
class GFG{

// Function to find the N-th
// Decakismyriagon Number
static int DecakismyriagonNum(int N)
{
    return (99998 * N * N - 99996 * N) / 2;
}

// Driver code
public static void main(String[] args)
{

    // Given Number N
    int N = 3;

    // Function Call
    System.out.println(DecakismyriagonNum(N));
}
}

// This code is contributed by Pratima Pandey

Python3

# Python3 program for the above approach

# Function to find the N-th
# Decakismyriagon Number
def DecakismyriagonNum(N):

    return (99998 * N * N - 99996 * N) // 2;

# Driver Code

# Given Number N
N = 3;

# Function Call
print(DecakismyriagonNum(N));

# This code is contributed by Code_Mech

C#

// C# program for the above approach
using System;
class GFG{

// Function to find the N-th
// Decakismyriagon Number
static int DecakismyriagonNum(int N)
{
    return (99998 * N * N - 99996 * N) / 2;
}

// Driver code
public static void Main()
{

    // Given Number N
    int N = 3;

    // Function Call
    Console.Write(DecakismyriagonNum(N));
}
}

// This code is contributed by Code_Mech

Javascript

<script>

// JavaScript program for the above approach

// Function to find the N-th
// Decakismyriagon Number
function DecakismyriagonNum(N) {
    return (99998 * N * N - 99996 * N) / 2;
}

// Driver Code

// Given Number N
let N = 3;

// Function Call
console.log(DecakismyriagonNum(N));

// This code is contributed by blalverma92
</script>

Output:

299997

Time Complexity: O(1)