Ako, I understand your process, but the last part of arithmetic is wrong.
We know that the first term in the sequence in numbers between is 17/3 which's ceiling is 6, and (17/3)^2, which's floor is 32.
The sequence is as follow:
(6, 7, 8, ...., 30, 31, 32)
So we have to find the number of terms between 6 and 32 inclusive, which is 32 - 6 + 1 and that is 27, we have to do this because subtraction only includes 1 of the values not both of them.
Or we could've done it by subtracting 5 from every term in the sequence then you would get:
(6-5, 7-5, 8-5, ...., 30-5, 31-5, 32-5)
(1, 2, 3, ..., 25, 26, 27)
Either way you can see that there are 27 terms, so the answer is 27 integers.