For Fibonacci (or indeed the result of most mathematical calculations) it makes no sense but I use this kind of thing all the time where the expected output is

For Fibonacci (or indeed the result of most mathematical calculations) it makes no sense but I use this kind of thing all the time where the expected output is, for example, a templated string like an error message. There are plenty of kinds of test outputs where rewriting the test and eyeballing the result is quicker, easier and ultimately better.