Nonagonal number
A nonagonal number is a figurate number that extends the concept of triangular and square numbers to the nonagon. Specifically, the nth nonagonal numbers count the number of dots in a pattern of n nested nonagons (9 sided polygons), all sharing a common corner, where the ith nonagon in the pattern has sides made of i dots spaced one unit apart from each other.
Examples :
Input : n = 10 n (7n - 5) / 2 10 * (7 * 10 - 5) / 2 10 * 65 / 2 = 325 Output :325 Input : 15 Output :750
The nth nonagonal number is given by the formula: n (7n – 5) / 2.
C++
// CPP Program to find // nth nonagonal number. #include <bits/stdc++.h> using namespace std; // Function to find nth // nonagonal number. int Nonagonal( int n) { // Formula to find nth // nonagonal number. return n * (7 * n - 5) / 2; } // Driver function. int main() { int n = 10; cout << Nonagonal(n); return 0; } |
Java
// Java Program to find // nth nonagonal number. import java.io.*; class GFG { // Function to find nth // nonagonal number. static int Nonagonal( int n) { // Formula to find nth // nonagonal number. return n * ( 7 * n - 5 ) / 2 ; } // Driver function. public static void main(String args[]) { int n = 10 ; System.out.println(Nonagonal(n)); } } // This code is contributed by Nikita Tiwari. |
Python3
# Python 3 Program to find # nth nonagonal number. # Function to find nth # nonagonal number. def Nonagonal(n): # Formula to find nth # nonagonal number. return int (n * ( 7 * n - 5 ) / 2 ) n = 10 print (Nonagonal(n)) # This code is contributed by # Smitha Dinesh Semwal |
C#
// C# Program to find // nth nonagonal number. using System; class GFG { // Function to find nth // nonagonal number. static int Nonagonal( int n) { // Formula to find nth // nonagonal number. return n * (7 * n - 5) / 2; } // Driver function. public static void Main() { int n = 10; Console.Write(Nonagonal(n)); } } // This code is contributed by vt_m. |
PHP
<?php // PHP Program to find // nth nonagonal number. // Function to find nth // nonagonal number. function Nonagonal( $n ) { // Formula to find nth // nonagonal number. return $n * (7 * $n - 5) / 2; } // Driver Code $n = 10; echo Nonagonal( $n ); // This code is contributed by vt_m. ?> |
Javascript
<script> // Javascript Program to find // nth nonagonal number. // Function to find nth // nonagonal number. function Nonagonal(n) { // Formula to find nth // nonagonal number. return parseInt(n * (7 * n - 5) / 2); } // Driver function. let n = 10; document.write(Nonagonal(n)); // This code is contributed by souravmahato348. </script> |
Output :
325
Time Complexity: O(1)
Auxiliary Space: O(1)
Given a number n, find nonagonal number series till n terms.
C++
// CPP Program find first // n nonagonal number. #include <bits/stdc++.h> using namespace std; // Function to find nonagonal // number series. int Nonagonal( int n) { for ( int i = 1; i <= n; i++) { cout << i * (7 * i - 5) / 2; cout << " " ; } } // Driver Code int main() { int n = 10; Nonagonal(n); return 0; } |
Java
// Java Program find first // n nonagonal number. import java.io.*; class GFG { // Function to find nonagonal // number series. static void Nonagonal( int n) { for ( int i = 1 ; i <= n; i++) { System.out.print(i * ( 7 * i - 5 ) / 2 ); System.out.print( " " ); } } // Driver Code public static void main(String args[]) { int n = 10 ; Nonagonal(n); } } // This code is contributed // by Nikita Tiwari. |
Python3
# Python 3 Program find first # n nonagonal number. # Function to find nonagonal # number series. def Nonagonal(n): for i in range ( 1 , n + 1 ): print ( int (i * ( 7 * i - 5 ) / 2 ),end = " " ) # driver Function n = 10 Nonagonal(n) # This code is contributed by # Smitha Dinesh Semwal |
C#
// C# Program find first // n nonagonal number. using System; class GFG { // Function to find nonagonal // number series. static void Nonagonal( int n) { for ( int i = 1; i <= n; i++) { Console.Write(i * (7 * i - 5) / 2); Console.Write( " " ); } } // Driver Code public static void Main() { int n = 10; Nonagonal(n); } } // This code is contributed by vt_m. |
PHP
<?php // PHP Program find first // n nonagonal number. // Function to find nonagonal // number series. function Nonagonal( $n ) { for ( $i = 1; $i <= $n ; $i ++) { echo $i * (7 * $i - 5) / 2; echo " " ; } } // Driver Code $n = 10; Nonagonal( $n ); // This code is contributed by ajit ?> |
Javascript
<script> // Javascript Program find first // n nonagonal number. // Function to find nonagonal // number series. function Nonagonal(n) { for (let i = 1; i <= n; i++) { document.write(parseInt(i * (7 * i - 5) / 2) + " " ); } } // Driver Code let n = 10; Nonagonal(n); </script> |
Output :
1 9 24 46 75 111 154 204 261 325
Time Complexity: O(n)
Auxiliary Space: O(1)
Reference:https://en.wikipedia.org/wiki/Nonagonal_number