# Sum of Linear Number Sequence

This calculator deals with 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, `3`

as the difference between successive figures, `29`

as the final value and `98`

as the sum of all numbers.

## A practical example.

We're selling photo storage in the cloud. Customers pay us an amount of money that's directly proportional to the amount of data that they upload - `$1 per 1 Gigabyte`

. Alice initially uploads `5GB`

of family photos and then adds `2GB`

per month. 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 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 |