I believe the answer is 2 to the power 32 which is 4,294,967,295 but I may have misunderstood your question.
Im assuming that by "linear notes" you mean each note is the same pitch, so really you're talking about percussive hits. The number of note combinations in a bar (with a maximum resolution of 32nd notes) would be however many notges your instrument can play, to the power of 32.
Also - how is an 8th rest a note? And by the above reasoning a ghost snare would still be a percussive hit (just a very soft one).
I went on the understanding that you can have a maximum of 32 equally spaced snare hits in a bar and you wanted to know the number of combinations of placing snares to non-snares that is possible. The answer is 2 to the power of 32.