Chain of numbers
This task is about continuing number patterns and finding a rule.
A chain of numbers begins: 1 3
This could be continued several ways.


a) 
1 3 5 7 9
What is the rule for continuing this chain? ____________________________________


b) 
1 3 9 27 81
What is the rule for continuing this chain? ____________________________________


c) 
1 3 7 15 31 63
What is the rule for continuing this chain? ____________________________________


d)  i) 
Make up a different chain by writing down the next three numbers.
The chain starts with: 1 3 and keeps getting bigger.
1 3

ii) 
Write the rule for the chain you have written.
