What is this pattern 1, 2, 5, 6, 9?

5 Answers

1. +1,+3,+1,+3

   next up should be 10,13,14,17,18,21

2. +1+3+1+3

3. 1+1=2…2+3=5…5+1=6… 6+3=9…. 9+1=10… 10+3=13…. 13+1=14…. 14 +3=17.. etc. Its basically add 1, add 3, add 1.

4. What Is This Pattern

5. +1, +3 and repeat