Mersenne: Double checked residues

[Greg Hewgill]

I was looking through the list of double checked exponents and their
residues (lucas_v.txt) and noticed four exponents near the bottom that only
had one listed residue:

5510339,tompete,Tom,WT1,1070460990F198F8
5704913,jhertel,hstar-sc,WT5,26CF19E736BD10DA
5704957,jhertel,hstar-wb,WT5,BFB8E1CF9DC6DE9C
5757253,jhertel,hstar-sv,WT5,E63F0DA56CB5B8E9

Why is this?

Greg Hewgill