# Other types of sequence

**Fraction sequences**

In fractional sequences the numerator and the denominators of the sequence should be considered separately. For example

The numerators increase by 1 and the denominators increase by 3. Therefore the formula for the nth term in this example is:

**The Fibonacci Sequence**

In a **Fibonacci sequence**, a sequence must be generated by two numbers. It is also a sequence which cannot be written in terms of its position. For example:

1, 1, 2, 3, 5, 8, 13, 21, 34, 55……

This sequence is worked out by adding together the two previous terms:

1 + 1, 1 + 2, 2 + 3, 5 + 8, 8 + 13, 13 + 21, 21 + 34….