# Sum of a Linear Number Sequence Calculator

This calculator deals with finding the sum of a linear number sequence - a set of values where every consecutive one differs by the same amount from the previous one. An example would be 20, 23, 26, 29 - it's a sequence of `4`

numbers, with `20`

as the initial value, `29`

as the final value, and `3`

as the difference between the successive figures. The sum of all of these numbers is `98`

.

## A practical example.

Let's say we're selling storage space for photos of goats on the cloud. Customers pay us an amount of money that's directly proportional to the amount of data they upload - `$1 per 1 Gigabyte`

. Alice initially uploads `5GB`

of family photos and then adds an additional `2GB`

per month. For the purpose of our analytics, we want to know how much she stores after a year and how much her business is worth to us during that time. Below, you'll find a table with all of the values and a pre-filled calculator widget.

Month | Payment | Sum |
---|---|---|

1 | 5 | 5 |

2 | 7 | 12 |

3 | 9 | 21 |

4 | 11 | 32 |

5 | 13 | 45 |

6 | 15 | 60 |

7 | 17 | 77 |

8 | 19 | 96 |

9 | 21 | 117 |

10 | 23 | 140 |

11 | 25 | 165 |

12 | 27 | 192 |