The answer is 34.
The full sequence is called the Fibonachi series.
Your sequence is 3 5 8 13 21
3 + 5= 8
8 + 13 = 21
Therefore:
13 + 21 = 34
The next number will be 13+21 = 34
The sequence alternates between a number and that number plus one. After 2 comes 3, after 3 comes 12, after 12 comes 13, after 13 comes 52, and after 52 comes 53. Following this pattern, the next number after 53 would be 212, as it follows 52 multiplied by 4 (the previous non-incrementing number). Therefore, the next number in the sequence is 212.
22
16.
17 cause it is the next prime number
The next number will be 13+21 = 34
37
35
22
16.
17 cause it is the next prime number
37
37
18
the next number is 21 because it is adding the last number stated.
13
31