Wilfrid Keller informed me that David Broadhurst had found
25*2^130407 to be prime. I had searched that range & not found it.
My lresults.txt file reads, in pertinent part:
[Tue Mar 30 11:07:37 2004]
25*2^130407-1 is not prime. Res64: 0000000000000000 Time : 37.830
Using IBDWT : Mersenne fftlen = 7168, Proth fftlen = 14336, Used
fftlen = 10240
& repeating the test on my machine, a 2.5 g p4 gives the same result.
& repeating the test under linux, with the statically linked version
also replicates the error.
PFGW confirms that 25*2^130407-1 is prime.
The zero residue seems unusual.