Largest PRP of the form 10^x-y , (length x).
PRP to base 3,5,7.
This PRP failed with PFGW Version 3.7.10.64BIT.20150809.Win_Dev [GWNUM 28.6]
so I had to find it by using PARI-GP as a next alternative.
Date of submission : 3 june 2018.
http://www.worldofnumbers.com

To be completed...