Can anyone help me out?
On the front page of Primegrid it lists under "Other significant primes":
Should these be -1 forms as stated above it in the "Recent Significant Primes"?
That being the case what are the latest finds for 121·2^n+1 and 27·2^n+1 ?
I can see 121·2^674360+1 and 27·2^2218064+1 at http://www.rieselprime.de/
However with 121·2^n+1 searched up to 4,999,992 there is a 99.97% chance a bigger prime should have been found.