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Program to find the Nth number of the series 2, 10, 24, 44, 70…..
• Last Updated : 24 Mar, 2021

Given a number N, the task is to find the Nth (N may be up to 10^18) term of this series:

2, 10, 24, 44, 70…..

The answer can be very large so print answer under modulo 10^9+9.
Examples:

```Input: N = 2
Output: 10

Input: N = 5
Output: 70```

Approach:The formula for Nth term will be:

Nth term = 3*n*n – n

Below is the implementation of the above approach:

## C++

 `// CPP program to find``// the Nth term of the series``// 2, 10, 24, 44, 70.....` `#include ``using` `namespace` `std;` `#define mod 1000000009` `// function to return nth term of the series``int` `NthTerm(``long` `long` `n)``{``    ``long` `long` `x = (3 * n * n) % mod;``    ``return` `(x - n + mod) % mod;``}` `// Driver code``int` `main()``{` `// Get N``    ``long` `long` `N = 4;` `    ``// Get Nth term``    ``cout << NthTerm(N);` `    ``return` `0;``}`

## Java

 `// Java program to find N-th``// term of the series:` `import` `java.util.*;``import` `java.lang.*;``import` `java.io.*;` `class` `GFG {` `    ``// function to return nth term of the series``    ``static` `long` `NthTerm(``long` `n)``    ``{``        ``long` `x = (``3` `* n * n) % ``1000000009``;``        ``return` `(x - n + ``1000000009``) % ``1000000009``;``    ``}` `    ``// Driver Code``    ``public` `static` `void` `main(String args[])``    ``{` `        ``// Taking  n as 4``        ``long` `N = ``4``;` `        ``// Printing the nth term``        ``System.out.println(NthTerm(N));``    ``}``}`

## Python3

 `# Python 3 program to find  ``# N-th term of the series:  ``    ` `  ` `# Function for calculating  ``# Nth term of series  ``def` `NthTerm(N) :  ``    ` `    ``# return nth term``    ``x ``=` `(``3` `*` `N``*``N)``%` `1000000009``    ``return` `((x ``-` `N ``+` `1000000009``)``%` `1000000009``)  ``    ` `# Driver code  ``if` `__name__ ``=``=` `"__main__"` `:  ``        ` `    ``N ``=` `4``    ` `    ``# Function Calling  ``    ``print``(NthTerm(N))`

## C#

 `// C# program to find N-th``// term of the series:``using` `System;``class` `GFG``{` `// function to return nth``// term of the series``static` `long` `NthTerm(``long` `n)``{``    ``long` `x = (3 * n * n) % 1000000009;``    ``return` `(x - n + 1000000009) % 1000000009;``}` `// Driver Code``public` `static` `void` `Main()``{` `    ``// Taking n as 4``    ``long` `N = 4;` `    ``// Printing the nth term``    ``Console.Write(NthTerm(N));``}``}` `// This code is contributed``// by ChitraNayal`

## PHP

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## Javascript

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Output:
`44`

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