First of all, do you know that for ?

Then you must reduce to this formula using the strong Markov property. For instance, for the second one, the event means that the B.M. hits 1 before -1, and then (after ) it hits 2 before -1, and then (after ) it hits 3 before -1, and finally it hits 4 before -1. Try to write down this idea in a more formal way using Markov property, and use the formula I mentioned above.