What tool and options should I use in ViennaRNA in order to get the probability that each possible n-long sequence of bases in my input is double stranded? We are working on the entire transcriptome so this may be the entire range of transcript sizes and we are only talking about folding. In other words, for each position i in a sequence T and input number 20, what is the probability all positions i to i+19 are all paired with other bases from T? How would I go about getting this output?