Centered tridecagonal number

Last Updated : 20 May, 2022

Given a number n, the task is to find the nth Centered Tridecagonal Number.
A Centered tridecagonal number represents a dot at the center and other dots surrounding the center dot
in the successive tridecagonal(13 sided polygon) layer.

Examples :

Input : 2
Output : 14

Input : 9
Output : 469

centered tridecagonal number

Formula for nth Centered tridecagonal number:

CT_{n}= (13n(n-1)+2)/2

C++

// C++ Program to find nth
// centered tridecagonal number
#include <bits/stdc++.h>
using namespace std;

// Function to find nth centered
// tridecagonal number
int centeredTridecagonalNum(long int n)
{
    // Formula to calculate nth
    // centered tridecagonal number
    return (13 * n * (n - 1) + 2) / 2;
}

// Drivers code
int main()
{
    long int n = 3;
    cout << centeredTridecagonalNum(n);
    cout << endl;
    n = 10;
    cout << centeredTridecagonalNum(n);

    return 0;
}

// C Program to find nth
// centered tridecagonal number
#include <stdio.h>

// Function to find nth centered
// tridecagonal number
int centeredTridecagonalNum(long int n)
{
    // Formula to calculate nth
    // centered tridecagonal number
    return (13 * n * (n - 1) + 2) / 2;
}

// Drivers code
int main()
{
    long int n = 3;
    printf("%d\n",centeredTridecagonalNum(n));
    
    n = 10;
    printf("%d\n",centeredTridecagonalNum(n));

    return 0;
}

// This code is contributed by kothavvsaakash.

Java

// Java Program to find nth
// centered tridecagonal number
import java.io.*;

class GFG 
{

// Function to find nth centered
// tridecagonal number
static long centeredTridecagonalNum(long n)
{
    // Formula to calculate nth
    // centered tridecagonal number
    return (13 * n * (n - 1) + 2) / 2;
}

// Driver Code
public static void main (String[] args) 
{
    long n = 3;
    System.out.println(centeredTridecagonalNum(n));
    n = 10;
    System.out.println(centeredTridecagonalNum(n));
}
}

// This code is contributed by anuj_67.

Python3

# Program to find nth centered 
# tridecagonal number

# Function to find centered
# tridecagonal number
def centeredTridecagonalNum(n) :
    
    # Formula to calculate nth
    # centered tridecagonal number
    return (13 * n * 
           (n - 1) + 2) // 2

# Driver Code
if __name__ == '__main__' :
        
    n = 3
    print(centeredTridecagonalNum(n))
    n = 10
    print(centeredTridecagonalNum(n))
                
# This code is contributed
# by akt_mit

// C# Program to find nth
// centered tridecagonal number
using System;

class GFG 
{

// Function to find nth centered
// tridecagonal number
static long centeredTridecagonalNum(long n)
{
    // Formula to calculate nth
    // centered tridecagonal number
    return (13 * n * (n - 1) + 2) / 2;
}

// Driver Code
public static void Main () 
{
    long n = 3;
    Console.WriteLine(centeredTridecagonalNum(n));
    n = 10;
    Console.WriteLine(centeredTridecagonalNum(n));
}
}

// This code is contributed by anuj_67.

PHP

<?php
// PHP Program to find nth
// centered tridecagonal number

// Function to find nth centered
// tridecagonal number
function centeredTridecagonalNum( $n)
{
    // Formula to calculate nth
    // centered tridecagonal number
    return (13 * $n * 
           ($n - 1) + 2) / 2;
}

// Driver Code
$n = 3;
echo centeredTridecagonalNum($n);
echo"\n";

$n = 10;
echo centeredTridecagonalNum($n);

// This code is contributed by anuj_67.
?>

JavaScript

<script>

// Javascript program to find nth
// centered tridecagonal number

// Function to find nth centered
// tridecagonal number
function centeredTridecagonalNum(n)
{
    
    // Formula to calculate nth
    // centered tridecagonal number
    return (13 * n * (n - 1) + 2) / 2;
}

// Driver code
var n = 3;
document.write(centeredTridecagonalNum(n) + "<br>");
 
n = 10;
document.write(centeredTridecagonalNum(n));

// This code is contributed by Ankita saini

</script>

Output :

40
586

Time Complexity: O(1)
Auxiliary Space: O(1)
Reference: http://oeis.org/wiki/Figurate_numbers

Centered Octagonal Number

jit_t

Improve

Article Tags :

Practice Tags :

Centered tridecagonal number

Similar Reads

Thank You!

What kind of Experience do you want to share?