Answer:
On an unweighted die, regardless of how many successes you've had, your chance of rolling a five will be one in six.
The chance of you rolling a die 16 times and getting a five each time would be 1/616, or 0.00000000000035447042.
The chance of rolling a die 16 times and getting the same number (regardless of what that number is) each time, would be 1/615, or 0.00000000000212682249
Regardless of how slim that chance is though, your chance on the next roll will still be 1/6.
However, if this is meant as a "real world" question, then your chances of rolling the same number so many times in a row is so low that at that point, your odds would be much higher of there being something odd with the die, or with your experiment. At that point, it would be sensible to say that the odds are very good of rolling another 5, regardless of the math, as there seems to be another factor affecting your outcome.