what is the rule for the pattern 3 6 9 12

what is the rule for the pattern 3 6 9 12

what is the rule for the pattern 3 6 9 12. There are any references about what is the rule for the pattern 3 6 9 12 in here. you can look below.

Showing posts matching the search for what is the rule for the pattern 3 6 9 12