Answer:
1 + 2 + 4 + 7 + 11 + 16 + 22 + 29 + 37 + 46
I may have given more. I think it was like this.
You add one to 1 and you get two. Then add two to 2 and you get four and then add three to 4 and then there is 7. I think this is how it goes.
I hope you understood :)