Centered heptagonal number
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)