I believe there are 2 typos in the readme for the index files. First, this line, "Referring to the table below, you should grab index files 5203 through 5209." I think should read, "Referring to the table below, you should grab index files 5203 through 5206 and 4107-4109." Second I think the file listed in the table, index-4107-.fits should not have the - and should read index-4107.fits.
https://github.com/dstndstn/astrometry.net/blob/main/doc/readme.rst
I believe there are 2 typos in the readme for the index files. First, this line, "Referring to the table below, you should grab index files 5203 through 5209." I think should read, "Referring to the table below, you should grab index files 5203 through 5206 and 4107-4109." Second I think the file listed in the table, index-4107-.fits should not have the - and should read index-4107.fits. https://github.com/dstndstn/astrometry.net/blob/main/doc/readme.rst