Is it reasonable to cite published computational results rather than reproduce them yourself?
I treat computational results as in silico experiments. They have been published in a peer-reviewed journal, so I trust them by default, unless I have a reason not to. I cite them without a need to recompute them.
Sometimes, I have a reason to doubt them: they don't match my intuition, or they don't match my own results in a related case; they seem incoherent; they don't match experimental data; etc. Then, I redo them, possibly in more than one way (different software, try checking the effect of some of the assumptions, etc.). If I learn something from it, I consider publishing this study.