16.17.19.22.27 () 48.69. Why is 45 in brackets

16.17.19.22.27 () 48.69. Why is 45 in brackets

16 17 19 22 27 () 48 69
1 2 3 5 () () 21
The second line is the difference between the two numbers in the previous line
Obviously: 3 = 2 + 1, 5 = 3 + 2
I guess the last two are 3 + 5 = 8, 5 + 8 = 13
And the last one is 21 = 13 + 8
So the missing number in the previous line is 27 + 8 = 35
It's not like 45