Sieve limit of 2.5*10^13, PRP tests in base 3, 5, 7, 11 and 13 with PFGW.

(275^65536+53^65536)/2 is 3-PRP! (875.7825s+0.0093s)
(275^65536+53^65536)/2 is 5-PRP! (1141.2041s+0.0076s)
(275^65536+53^65536)/2 is 7-PRP! (1146.9024s+0.0076s)
(275^65536+53^65536)/2 is 11-PRP! (1137.0047s+0.0093s)
(275^65536+53^65536)/2 is 13-PRP! (1096.4501s+0.0119s)

To be completed...