Located in this directory are the mappability scores for all human chromosomes for reads lengths of 27, 36 and 50bp,
The chromosomes were originally downloaded from Ensembl v.42.

The files are named thusly:
    <chromosome name>.<k>mappability

For example:
   Homo_sapiens.NCBI36.42.dna.chromosome.4.fa.50mappability
Contains the data for chromosome 4, for 50mers.

The file format is fasta like.  However, every 2 character sin the "sequence" should be used as a score for the corresponding base in the chromosomal sequence.
It also follows for a chromosome of size N, there are N*2 characters in the mappability file.
Thus the following scores:
  1211100908070707080910111213141516
Should be interpreted as:
  12 11 10 9 8 7 7 7 8 9 10 11 12 13 14 15 16