A sequence is a list of things (usually numbers) that are in order. The simplest of them is an arithmetic series. An arithmetic series is a sequence of numbers such that the difference of any two successive members is a constant. USolver provides a easy way to generate sequences with ".." operator.
The rule is simple. You provide first and last number of the sequence and apply ".." between them, assuming that the step is 1. If the step is not 1, then provide first and second number of the sequence so that USolver knows how to build it.
You can apply more then one rule in a single sequence. For example, the sequence:
When there are more then one ".." operator within the same sequence, USolver will take previous two values to figure out the pattern and will apply it until it reaches the last number of the sequence.
Sometimes, you do not know what is the last number of the sequence or it is difficult to calculate it. In this case you can tell USolver how many numbers you need in a series.
This is particularly useful when your first and second numbers in the sequence are variables. For example, you can define:
Where I used cells A1 and A2 to generate my sequence. Now, cells A1 and A2 can be linked to user input fields and you still get consistent result regardless what user enters.
Another most common sequence is a gemetric series. It is different because it uses a different kind of rule to calculate next sequence number. For example following rule calculates next number by multiplying previous by 2.
As you can see in the example above, you can provide an operator before the second sequence number to define geometric series. There are 3 operators that you can use in a geometric series: "*", "/", "^". Note that you cannot use "+" and "-" as they are unary operators.
Even Numbers 0, 2, 4, 6, 8
Odd Numbers 1, 3, 5, 7, 9
Power of 2 1, 2, 4, 8, 16, 32
Alternate Series 1, -2, 3, -4, 5