Since the terms of the given sequence differ by different numbers, then the terms would start a new pattern, so that the other term of the sequence is 23.
16 26 21 13 23 18 10...
26
If you mean: 1 1 2 3 5 8 13 21 then the next number is 13+21 = 34
The next number will be 13+21 = 34
21
If you mean: 1 2 3 5 8 13 then the next number is 8+13 = 21
the next number is 21 because it is adding the last number stated.
24, they are going up in 3's, 13, 16, 19 and 18, 21 so next number is 24.
24
the answer will be 21
24
34
35