# Octagonal number

Here given code implementation process.

``````// C Program for
// Octagonal number
#include <stdio.h>

void octagonalNo(int k)
{
// Print all initial k octagonal number
for (int n = 1; n <= k; ++n)
{
// Formula
//  (3n²-2n)

// Calculate nth octagonal number
int result = (3 *(n *n) - 2 *n);

// Display calculated result
printf("  %d", result);
}
}
int main()
{
//  Octagonal number are
// —————————————————————————————————————————————
//  1, 8, 21, 40, 65, 96, 133, 176, 225, 280,
// 341, 408, 481, 560, 645, 736, 833, 936, 1045, 1160,
// 1281, 1408, 1541, 1680, 1825, 1976, 2133, 2296, 2465,
// 2640, 2821, 3008, 3201, 3400, 3605, 3816, 4033,
// 4256, 4485, 4720 etc.
// k = 10
octagonalNo(10);
return 0;
}``````

#### Output

``  1  8  21  40  65  96  133  176  225  280``
``````// Java program for
// Octagonal number
public class OctagonalNumber
{
public void octagonalNo(int k)
{
// Print all initial k octagonal number
for (int n = 1; n <= k; ++n)
{
// Formula
// (3n²-2n)

// Calculate nth octagonal number
int result = (3 * (n * n) - 2 * n);

// Display calculated result
System.out.print(" " + result);
}
}
public static void main(String[] args)
{
//  Octagonal number are
// —————————————————————————————————————————————
//  1, 8, 21, 40, 65, 96, 133, 176, 225, 280,
// 341, 408, 481, 560, 645, 736, 833, 936, 1045, 1160,
// 1281, 1408, 1541, 1680, 1825, 1976, 2133, 2296, 2465,
// 2640, 2821, 3008, 3201, 3400, 3605, 3816, 4033,
// 4256, 4485, 4720 etc.

// k = 10
}
}``````

#### Output

`` 1 8 21 40 65 96 133 176 225 280``
``````// Include header file
#include <iostream>
using namespace std;
// C++ program for
// Octagonal number

class OctagonalNumber
{
public: void octagonalNo(int k)
{
// Print all initial k octagonal number
for (int n = 1; n <= k; ++n)
{
// Formula
// (3n²-2n)

// Calculate nth octagonal number
int result = (3 *(n *n) - 2 *n);

// Display calculated result
cout << " " << result;
}
}
};
int main()
{
//  Octagonal number are
// —————————————————————————————————————————————
//  1, 8, 21, 40, 65, 96, 133, 176, 225, 280,
// 341, 408, 481, 560, 645, 736, 833, 936, 1045, 1160,
// 1281, 1408, 1541, 1680, 1825, 1976, 2133, 2296, 2465,
// 2640, 2821, 3008, 3201, 3400, 3605, 3816, 4033,
// 4256, 4485, 4720 etc.

// k = 10
return 0;
}``````

#### Output

`` 1 8 21 40 65 96 133 176 225 280``
``````// Include namespace system
using System;
// Csharp program for
// Octagonal number
public class OctagonalNumber
{
public void octagonalNo(int k)
{
// Print all initial k octagonal number
for (int n = 1; n <= k; ++n)
{
// Formula
// (3n²-2n)

// Calculate nth octagonal number
int result = (3 * (n * n) - 2 * n);

// Display calculated result
Console.Write(" " + result);
}
}
public static void Main(String[] args)
{
//  Octagonal number are
// —————————————————————————————————————————————
//  1, 8, 21, 40, 65, 96, 133, 176, 225, 280,
// 341, 408, 481, 560, 645, 736, 833, 936, 1045, 1160,
// 1281, 1408, 1541, 1680, 1825, 1976, 2133, 2296, 2465,
// 2640, 2821, 3008, 3201, 3400, 3605, 3816, 4033,
// 4256, 4485, 4720 etc.

// k = 10
}
}``````

#### Output

`` 1 8 21 40 65 96 133 176 225 280``
``````package main
import "fmt"
// Go program for
// Octagonal number

func octagonalNo(k int) {
// Print all initial k octagonal number
for n := 1 ; n <= k ; n++ {
// Formula
// (3n²-2n)
// Calculate nth octagonal number
var result int = (3 * (n * n) - 2 * n)
// Display calculated result
fmt.Print(" ", result)
}
}
func main() {
//  Octagonal number are
// —————————————————————————————————————————————
//  1, 8, 21, 40, 65, 96, 133, 176, 225, 280,
// 341, 408, 481, 560, 645, 736, 833, 936, 1045, 1160,
// 1281, 1408, 1541, 1680, 1825, 1976, 2133, 2296, 2465,
// 2640, 2821, 3008, 3201, 3400, 3605, 3816, 4033,
// 4256, 4485, 4720 etc.

// k = 10
octagonalNo(10)
}``````

#### Output

`` 1 8 21 40 65 96 133 176 225 280``
``````<?php
// Php program for
// Octagonal number
class OctagonalNumber
{
public	function octagonalNo(\$k)
{
// Print all initial k octagonal number
for (\$n = 1; \$n <= \$k; ++\$n)
{
// Formula
// (3n²-2n)
// Calculate nth octagonal number
\$result = (3 * (\$n * \$n) - 2 * \$n);
// Display calculated result
echo(" ".\$result);
}
}
}

function main()
{
//  Octagonal number are
// —————————————————————————————————————————————
//  1, 8, 21, 40, 65, 96, 133, 176, 225, 280,
// 341, 408, 481, 560, 645, 736, 833, 936, 1045, 1160,
// 1281, 1408, 1541, 1680, 1825, 1976, 2133, 2296, 2465,
// 2640, 2821, 3008, 3201, 3400, 3605, 3816, 4033,
// 4256, 4485, 4720 etc.
// k = 10
}
main();``````

#### Output

`` 1 8 21 40 65 96 133 176 225 280``
``````// Node JS program for
// Octagonal number
class OctagonalNumber
{
octagonalNo(k)
{
// Print all initial k octagonal number
for (var n = 1; n <= k; ++n)
{
// Formula
// (3n²-2n)

// Calculate nth octagonal number
var result = (3 * (n * n) - 2 * n);

// Display calculated result
process.stdout.write(" " + result);
}
}
}

function main()
{
//  Octagonal number are
// —————————————————————————————————————————————
//  1, 8, 21, 40, 65, 96, 133, 176, 225, 280,
// 341, 408, 481, 560, 645, 736, 833, 936, 1045, 1160,
// 1281, 1408, 1541, 1680, 1825, 1976, 2133, 2296, 2465,
// 2640, 2821, 3008, 3201, 3400, 3605, 3816, 4033,
// 4256, 4485, 4720 etc.
// k = 10
}
main();``````

#### Output

`` 1 8 21 40 65 96 133 176 225 280``
``````#  Python 3 program for
#  Octagonal number
class OctagonalNumber :
def octagonalNo(self, k) :
n = 1
#  Print all initial k octagonal number
while (n <= k) :
#  Formula
#  (3n²-2n)

#  Calculate nth octagonal number
result = (3 * (n * n) - 2 * n)

#  Display calculated result
print(" ", result, end = "")
n += 1

def main() :
#   Octagonal number are
#  —————————————————————————————————————————————
#   1, 8, 21, 40, 65, 96, 133, 176, 225, 280,
#  341, 408, 481, 560, 645, 736, 833, 936, 1045, 1160,
#  1281, 1408, 1541, 1680, 1825, 1976, 2133, 2296, 2465,
#  2640, 2821, 3008, 3201, 3400, 3605, 3816, 4033,
#  4256, 4485, 4720 etc.
#  k = 10

if __name__ == "__main__": main()``````

#### Output

``  1  8  21  40  65  96  133  176  225  280``
``````#  Ruby program for
#  Octagonal number
class OctagonalNumber
def octagonalNo(k)
n = 1
#  Print all initial k octagonal number
while (n <= k)
#  Formula
#  (3n²-2n)

#  Calculate nth octagonal number
result = (3 * (n * n) - 2 * n)

#  Display calculated result
print(" ", result)
n += 1
end

end

end

def main()
#   Octagonal number are
#  —————————————————————————————————————————————
#   1, 8, 21, 40, 65, 96, 133, 176, 225, 280,
#  341, 408, 481, 560, 645, 736, 833, 936, 1045, 1160,
#  1281, 1408, 1541, 1680, 1825, 1976, 2133, 2296, 2465,
#  2640, 2821, 3008, 3201, 3400, 3605, 3816, 4033,
#  4256, 4485, 4720 etc.

#  k = 10
end

main()``````

#### Output

`` 1 8 21 40 65 96 133 176 225 280``
``````// Scala program for
// Octagonal number
class OctagonalNumber()
{
def octagonalNo(k: Int): Unit = {
var n: Int = 1;
// Print all initial k octagonal number
while (n <= k)
{
// Formula
// (3n²-2n)

// Calculate nth octagonal number
var result: Int = (3 * (n * n) - 2 * n);

// Display calculated result
print(" " + result);
n += 1;
}
}
}
object Main
{
def main(args: Array[String]): Unit = {
var task: OctagonalNumber = new OctagonalNumber();
//  Octagonal number are
// —————————————————————————————————————————————
//  1, 8, 21, 40, 65, 96, 133, 176, 225, 280,
// 341, 408, 481, 560, 645, 736, 833, 936, 1045, 1160,
// 1281, 1408, 1541, 1680, 1825, 1976, 2133, 2296, 2465,
// 2640, 2821, 3008, 3201, 3400, 3605, 3816, 4033,
// 4256, 4485, 4720 etc.

// k = 10
}
}``````

#### Output

`` 1 8 21 40 65 96 133 176 225 280``
``````// Swift 4 program for
// Octagonal number
class OctagonalNumber
{
func octagonalNo(_ k: Int)
{
var n: Int = 1;
// Print all initial k octagonal number
while (n <= k)
{
// Formula
// (3n²-2n)

// Calculate nth octagonal number
let result: Int = (3 * (n * n) - 2 * n);

// Display calculated result
print(" ", result, terminator: "");
n += 1;
}
}
}
func main()
{
//  Octagonal number are
// —————————————————————————————————————————————
//  1, 8, 21, 40, 65, 96, 133, 176, 225, 280,
// 341, 408, 481, 560, 645, 736, 833, 936, 1045, 1160,
// 1281, 1408, 1541, 1680, 1825, 1976, 2133, 2296, 2465,
// 2640, 2821, 3008, 3201, 3400, 3605, 3816, 4033,
// 4256, 4485, 4720 etc.
// k = 10
}
main();``````

#### Output

``  1  8  21  40  65  96  133  176  225  280``
``````// Kotlin program for
// Octagonal number
class OctagonalNumber
{
fun octagonalNo(k: Int): Unit
{
var n: Int = 1;
// Print all initial k octagonal number
while (n <= k)
{
// Formula
// (3n²-2n)

// Calculate nth octagonal number
val result: Int = (3 * (n * n) - 2 * n);

// Display calculated result
print(" " + result);
n += 1;
}
}
}
fun main(args: Array < String > ): Unit
{
//  Octagonal number are
// —————————————————————————————————————————————
//  1, 8, 21, 40, 65, 96, 133, 176, 225, 280,
// 341, 408, 481, 560, 645, 736, 833, 936, 1045, 1160,
// 1281, 1408, 1541, 1680, 1825, 1976, 2133, 2296, 2465,
// 2640, 2821, 3008, 3201, 3400, 3605, 3816, 4033,
// 4256, 4485, 4720 etc.
// k = 10
}``````

#### Output

`` 1 8 21 40 65 96 133 176 225 280``

## Comment

Please share your knowledge to improve code and content standard. Also submit your doubts, and test case. We improve by your feedback. We will try to resolve your query as soon as possible.