Find n-th term of series 2, 10, 30, 68, 130 …

Given a series 2, 10, 30, 68, 130 … Identify the pattern in the series and find the nth value in the series. Indices are starting from 1 . 1 <= n <= 200

Examples: 

Input : n = 12
Output : 1740

Input : n = 200
Output : 8000200

If observed carefully, the pattern of the series can be noticed as n^3 + n.

Below is the implementation of the above approach: 

C++

// C++ program to find n-th value
#include <bits/stdc++.h>
using namespace std;

// Function to find nth term
int findValueAtX(int n)
{
    return (n * n * n) + n;
}

// drivers code
int main()
{
    cout << findValueAtX(10) << endl;
    cout << findValueAtX(2) << endl;
    return 0;
}

Java

// Java program to find n-th value
import java.io.*;

class GFG {

    // Function to find nth term
    static int findValueAtX(int n)
    {
        return (n * n * n) + n;
    }

    // driver code
    public static void main(String[] args)
    {
        System.out.println(findValueAtX(10));
        System.out.println(findValueAtX(2));
    }
}

// This code is contributed by vt_m.

Python3

# Python3 program to find n-th value

# Function to find nth term
def findValueAtX(n):
    return (n * n * n) + n

# Driver Code
print(findValueAtX(10))
print(findValueAtX(2))

# This code is contributed by Azkia Anam.

C#

// C# program to find n-th value
using System;

class GFG {

    // Function to find nth term
    static int findValueAtX(int n)
    {
        return (n * n * n) + n;
    }

    // driver code
    public static void Main()
    {
        Console.WriteLine(findValueAtX(10));
        Console.WriteLine(findValueAtX(2));
    }
}

PHP

<?php
// PHP program to
// find n-th value

// Function to find nth term
function findValueAtX($n)
{
    return ($n * $n * $n) + $n;
}

    // Driver Code
    echo findValueAtX(10),"\n";
    echo findValueAtX(2);

// This code is contributed by anuj_67.
?>

Javascript

<script>

    // JavaScript program to find n-th value

    // Function to find nth term
    function findValueAtX(n)
    {
        return (n * n * n) + n;
    }

    document.write(findValueAtX(10) + "</br>");
      document.write(findValueAtX(2));

</script>

Output

1010
10

Time Complexity:  O(1)
Auxiliary Space: O(1)