Taking a look at the examples again Sequence. This algebra video tutorial provides a basic introduction into recursive formulas and how to use it to find the first four terms or the nth term of a sequenc. This formula can also be defined as Arithmetic Sequence Recursive Formula.
To find the recursive formula start by looking at the differences and ratios of consecutive terms.
Begin casesa 1 3leftarrowgray text the first term is 3 a n a n-12leftarrowgray text add 2 to the previous term end cases. As you can observe from the sequence itself it is an arithmetic sequence which includes the first term followed by other terms and a common difference d between each term is the number you add or subtract to them. An n 1 Recursive formula. To evaluate this we have to figure out what b of three is so lets write that down.