Given a number n, the task is to find nth Centered heptagonal number.
Centered heptagonal number is centered figure number that represents a heptagon with dot in center and all other dot surrounding in heptagonal form. Nth centered heptagonal number can be calculated by using formula (7n2 – 7n + 2) / 2.
Examples :
Input : n = 2 Output : 8 Input : n = 7 Output : 148
Please refer this diagram for pictorial representation.
Below is the implementation :
C++
// CPP program to find n-th // Centered heptagonal number #include <bits/stdc++.h> using namespace std;
// Function to find Centered // heptagonal number int centered_heptagonal_num( long int n)
{ // Formula to calculate nth
// Centered heptagonal number
return (7 * n * n - 7 * n + 2) / 2;
} // Driver Code int main()
{ long int n = 5;
cout << n << "th Centered heptagonal number : " ;
cout << centered_heptagonal_num(n);
return 0;
} |
C
// C program to find n-th // Centered heptagonal number #include <stdio.h> // Function to find Centered // heptagonal number int centered_heptagonal_num( long int n)
{ // Formula to calculate nth
// Centered heptagonal number
return (7 * n * n - 7 * n + 2) / 2;
} // Driver Code int main()
{ long int n = 5;
printf ( "%ldth Centered heptagonal number : " ,n);
printf ( "%d" ,centered_heptagonal_num(n));
return 0;
} // This code is contributed by kothavvsaakash. |
Java
// Java program to find n-th Centered // heptagonal number import java.io.*;
class GFG {
// Function to find Centered heptagonal
// number
static long centered_heptagonal_num( long n)
{
// Formula to calculate nth
// Centered heptagonal number
return ( 7 * n * n - 7 * n + 2 ) / 2 ;
}
// Driver Code
public static void main (String[] args)
{
long n = 5 ;
System.out.println( n + "th Centered "
+ "heptagonal number : "
+ centered_heptagonal_num(n));
}
} // This code is contributed by anuj_67. |
Python3
# Python program to find nth # Centered heptagonal number # Function to find Centered # heptagonal number def centered_heptagonal_num(n):
# Formula to calculate nth
# Centered heptagonal number
return ( 7 * n * n - 7 * n + 2 ) / / 2
# Driver Code n = 5
print ( "%sth Centered heptagonal number : " % n,
centered_heptagonal_num(n))
|
C#
//C# program to find n-th Centered // heptagonal number using System;
class GFG {
// Function to find Centered heptagonal
// number
static long centered_heptagonal_num( long n)
{
// Formula to calculate nth
// Centered heptagonal number
return (7 * n * n - 7 * n + 2) / 2;
}
// Driver Code
public static void Main ()
{
long n = 5;
Console.WriteLine( n + "th Centered "
+ "heptagonal number : "
+ centered_heptagonal_num(n));
}
} // This code is contributed by anuj_67. |
PHP
<?php // PHP program to find n-th // Centered heptagonal number // Function to find Centered // heptagonal number function centered_heptagonal_num( $n )
{ // Formula to calculate nth
// Centered heptagonal number
return (7 * $n * $n - 7 *
$n + 2) / 2;
} // Driver Code $n = 5;
echo $n , "th Centered heptagonal number : " ;
echo centered_heptagonal_num( $n );
// This code is contributed by m_kit ?> |
Javascript
<script> // Javascript program to find n-th // Centered heptagonal number // Function to find Centered // heptagonal number function centered_heptagonal_num(n)
{ // Formula to calculate nth
// Centered heptagonal number
return parseInt((7 * n * n - 7 * n + 2) / 2);
} // Driver Code let n = 5; document.write(n + "th Centered heptagonal number : " );
document.write(centered_heptagonal_num(n)); // This code is contributed by rishavmahato348. </script> |
Output :
5th Centered heptagonal number : 71
Time Complexity: O(1)
Auxiliary Space: O(1)