Number of cells in the Nth order figure

• Last Updated : 01 Apr, 2021

Given an integer N, the task is to find the number of cells in Nth order figure of the given type:

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Examples:

Input: N = 2
Output: 5
Input: N = 3
Output: 13

Approach: It can be observed that for the values of N = 1, 2, 3, … a series will be formed as 1, 5, 13, 25, 41, 61, 85, 113, 145, 181, … whose Nth term will be N2 + (N – 1)2.
Below is the implementation of the above approach:

C++

 `// C++ implementation of the approach``#include ``using` `namespace` `std;` `// Function to return the number``// of cells in the nth order``// figure of the given type``int` `cntCells(``int` `n)``{``    ``int` `cells = ``pow``(n, 2) + ``pow``(n - 1, 2);``    ``return` `cells;``}` `// Driver code``int` `main()``{``    ``int` `n = 3;` `    ``cout << cntCells(n);` `    ``return` `0;``}`

Java

 `// Java implementation of the approach``class` `GFG``{``    ` `// Function to return the number``// of cells in the nth order``// figure of the given type``static` `int` `cntCells(``int` `n)``{``    ``int` `cells = (``int``)Math.pow(n, ``2``) +``                ``(``int``)Math.pow(n - ``1``, ``2``);``    ``return` `cells;``}` `// Driver code``public` `static` `void` `main(String[] args)``{``    ``int` `n = ``3``;` `    ``System.out.println(cntCells(n));``}``}` `// This code is contributed by Code_Mech`

Python3

 `# Python3 implementation of the approach` `# Function to return the number``# of cells in the nth order``# figure of the given type``def` `cntCells(n) :` `    ``cells ``=` `pow``(n, ``2``) ``+` `pow``(n ``-` `1``, ``2``);``    ` `    ``return` `cells;` `# Driver code``if` `__name__ ``=``=` `"__main__"` `:` `    ``n ``=` `3``;` `    ``print``(cntCells(n));` `# This code is contributed by AnkitRai01`

C#

 `// C# implementation of the approach``using` `System;``    ` `class` `GFG``{``    ` `// Function to return the number``// of cells in the nth order``// figure of the given type``static` `int` `cntCells(``int` `n)``{``    ``int` `cells = (``int``)Math.Pow(n, 2) +``                ``(``int``)Math.Pow(n - 1, 2);``    ``return` `cells;``}` `// Driver code``public` `static` `void` `Main(String[] args)``{``    ``int` `n = 3;` `    ``Console.WriteLine(cntCells(n));``}``}` `// This code is contributed by 29AjayKumar`

Javascript

 ``
Output:
`13`

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