I would like to find a short sequence (25 bp) that does not match anywhere within Human Reference Genome (hg38/hg19) through R scripts. I am not sure if there is a quick solution to do what I am looking for. So, I guess it would be solve, if I can create a list of random 25 bp fragments and then do an alignment. Ultimately, the lowest score output could be the supposed answer! If it might be a correct approach to do, could you please guide me how it can be done by R scripting. Thank you.