What comes next in this pattern 2123262102?

Answer 1

Seperate like this: 2 1 2 3 2 6 2 10 2 ?

then categorize them two by two:

2 1

2 3

2 6

2 10

2 ?

now this is the question : 1 3 6 10 ? and the answer is 15"

1 + 2 = 3 ---> + 3 = 6 ----> + 4 = 10 ----> + 5 =15