Sequences

A sequence is just a set of ordered numbers with a pattern.

Example: 2,4,6,8,10,12,14... and this can go on as long as you want.

In this case, each each number in the sequence is just twice it's position number.

The position number is represented by "n". The number in the sequence that corresponds to it is represented by a_n

n	1	2	3	4	5	6	7
_	a1	a2	a3	a4	a5	a6	a7
an	2	4	6	8	10	12	14

But, it is shorter to just write down the pattern's rule, so that someone else can just create the sequence themselves. So, you would therefore write that as a_n={2n}

You can do some more complex things like: 0,1,5,23,119,719 or These look like they have no pattern, but they do. a_n={n!-1}

Making it easier to understand is another good reason to write the sequence in notation rather than as a string of numbers.

Continue

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Quick Quiz

Quick Quiz
1. If a_n={n²+5} ,write the first 5 numbers in the sequence

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