What number is missing here?
2, 3, 5, 8, 13. ?

so the answer must be 21, right? this will be 21, in this sequence every next digit is the sum of previous two digits as5=3+2 ,next 8=5+3 then 13= 5+8 hence the next will be 8+13=21 . 21

^•^

2, 3, 5, 8, 13 missing number is 18.

goog may have it for you