Will Carington, works for Noodle
The type of patterns/sequences covered in the "Ability" section of the TACHS exam could involve numbers – you could be asked to identify a pattern in a series of numbers, for example. Other types of patterns include visual patterns – for example, you could be asked to identify patterns among a group of shapes.
I'd recommend looking at some practice problems. This practice test from the TACHS website includes sample questions from the "Ability" section on pages 37-40.
Hope this helps, and best of luck!