You start from 1 and add the last two numbers in the sequence, and continue.
Therefore, to start, you'd do 1 + 0 = 1.
This gives you a sequence of 1, 1, ...
Similarly, you do 1 + 1 = 2.
That's a sequence of 1, 1, 2, ... now.
And you keep repeating:
1 + 2 = 3 (1, 1, 2, 3, ...)
2 + 3 = 5 (1, 1, 2, 3, 5, ...)
3 + 5 = 8 (1, 1, 2, 3, 5, 8, ...)
Therefore, the next three numbers would follow this pattern:
8 + 5 = 13 (1, 1, 2, 3, 5, 8, 13, ...)
13 + 8 = 21 (1, 1, 2, 3, 5, 8, 13, 21, ...)
21 + 13 = 34 (1, 1, 2, 3, 5, 8, 13, 21, 34, ...)
