Program to find Nth term of series 1, 6, 17, 34, 56, 86, 121, 162, …….

Given a number N. The task is to write a program to find the Nth term of the below series:

1, 6, 17, 34, 56, 86, 121, 162, …..(N Terms)

**Examples:**

Input: N = 4 Output: 34 For N = 4 4th Term = ( 3 * 4 * 4 - 4 * 4 + 2) = 34 Input: N = 10 Output: 261

**Approach:** The generalized Nth term of this series:

Below is the required implementation:

## C++

`// C++ program to find the N-th term of the series:` `// 1, 6, 17, 34, 56, 86, 121, 162, .....` `#include <iostream>` `#include <math.h>` `using` `namespace` `std;` `// calculate Nth term of series` `int` `nthTerm(` `int` `n)` `{` ` ` `return` `3 * ` `pow` `(n, 2) - 4 * n + 2;` `}` `// Driver code` `int` `main()` `{` ` ` `int` `N = 4;` ` ` `cout << nthTerm(N) << endl;` ` ` `return` `0;` `}` |

## Java

`// Java program to find the N-th term of the series:` `// 1, 6, 17, 34, 56, 86, 121, 162, .....` `public` `class` `GFG {` ` ` ` ` `// calculate Nth term of series` ` ` `static` `int` `nthTerm(` `int` `n)` ` ` `{` ` ` `return` `3` `* (` `int` `) Math.pow(n, ` `2` `) - ` `4` `* n + ` `2` `;` ` ` `}` ` ` ` ` `// Driver code` ` ` `public` `static` `void` `main(String args[])` ` ` `{` ` ` `int` `N = ` `4` `;` ` ` ` ` `System.out.println(nthTerm(N));` ` ` ` ` `}` ` ` `// This Code is contributed by ANKITRAI1` `}` |

## Python3

`# Python program to find the` `# N-th term of the series:` `# 1, 6, 17, 34, 56, 86, 121, 162, .....` `# calculate Nth term of series` `def` `nthTerm(n):` ` ` `return` `3` `*` `pow` `(n, ` `2` `) ` `-` `4` `*` `n ` `+` `2` `# Driver code` `N ` `=` `4` `print` `(nthTerm(N))` `# This code is contributed by` `# Sanjit_Prasad` |

## C#

`// C# program to find the` `// N-th term of the series:` `// 1, 6, 17, 34, 56, 86, 121, 162, .....` `using` `System;` `class` `GFG` `{` ` ` `// calculate Nth term of series` `static` `int` `nthTerm(` `int` `n)` `{` ` ` `return` `3 * (` `int` `) Math.Pow(n, 2) -` ` ` `4 * n + 2;` `}` ` ` `// Driver code` `public` `static` `void` `Main()` `{` ` ` `int` `N = 4;` ` ` ` ` `Console.Write(nthTerm(N));` `}` `}` `// This code is contributed` `// by ChitraNayal` |

## PHP

`<?php` `// PHP program to find the` `// N-th term of the series:` `// 1, 6, 17, 34, 56, 86, 121, 162, .....` `// calculate Nth term of series` `function` `nthTerm(` `$n` `)` `{` ` ` `return` `3 * pow(` `$n` `, 2) -` ` ` `4 * ` `$n` `+ 2;` `}` `// Driver code` `$N` `= 4;` `echo` `nthTerm(` `$N` `).` `"\n"` `;` `// This code is contributed` `// by ChitraNayal` `?>` |

## Javascript

`<script>` `// JavaScript program to find the N-th term of the series:` `// 1, 6, 17, 34, 56, 86, 121, 162, .....` `// calculate Nth term of series` `function` `nthTerm(n)` `{` ` ` `return` `3 * Math.pow(n, 2) - 4 * n + 2;` `}` `// Driver code` `let N = 4;` ` ` `document.write( nthTerm(N) );` `// This code contributed by gauravrajput1` `</script>` |

**Output:**

34

**Time Complexity:** O(1)

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