LEGO is ideally suited for series as you can see the relation to the times table very easily.
The series can then be represented more imaginatively by building models based on the series. Problems like two light house with different sequences can be modelled and the overlapping interval visually found
makingpi 
Hi there,
I love your activity, and I would like to use it to teach Sequences and Series to my high school class. Can you recommend where I can get the lego pieces (hopefully for not too expensive).
Thank you,
Ilene
Yes try :
1) Wilko who now produce cheap blocks
2) buy used on ebay
3) Ask class for any old lego
Good luck