Mathematica can do nothing this expectation in general: [![enter image description here][1]][1] So, it is highly unlikely that this expectation can be expressed in terms of elementary, or even special, functions. However, we have this: [![enter image description here][2]][2] [1]: https://i.sstatic.net/RCJOv.png [2]: https://i.sstatic.net/s1z4e.png