Revision history [back]

This isn't an answer, but one thing that could be useful in general with integers is to do

assume(A,'integer')

But solve in general is via Maxima, which will assume you are using "normal" real or complex variables, and this doesn't help (because Maxima explicitly avoids your assumptions in solving, because it is assumed you are using dummy variables in solve commands).

I am not really sure how the domain parameter influences things.