FYI - there is something wrong with the FTP server:

$ wget ftp://surfer.nmr.mgh.harvard.edu/pub/dist/freesurfer/5.3.0-HCP/freesurfer-Linux-centos4_x86_64-stable-pub-v5.3.0-HCP.tar.gz
--2016-09-15 20:04:51--  ftp://surfer.nmr.mgh.harvard.edu/pub/dist/freesurfer/5.3.0-HCP/freesurfer-Linux-centos4_x86_64-stable-pub-v5.3.0-HCP.tar.gz
           => 'freesurfer-Linux-centos4_x86_64-stable-pub-v5.3.0-HCP.tar.gz'
Resolving surfer.nmr.mgh.harvard.edu (surfer.nmr.mgh.harvard.edu)... 132.183.202.158
Connecting to surfer.nmr.mgh.harvard.edu (surfer.nmr.mgh.harvard.edu)|132.183.202.158|:21... connected.
Error in server response. Closing.
Retrying.