Centered tridecagonal number

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 

Formula for nth Centered tridecagonal number: 

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

// 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#

// 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