Originally posted by vjs
considering we have tried up to the 45-digit level... Is there any reason to try P+1 with very high bounds?
I don't know. People differ on this subject. I've set up ECM server for OddPerfect.org so that it does one P+1 curve at each level, and works three levels above the ECM level. I like working ahead because P+1 and P-1 are faster than ECM and have about the same chance of finding a factor. You need multiple curves for P+1 because for each factor, half the start points won't find that factor. The traditional way to get this is to run three P+1 curves at each level, but I figure three curves at successively higher levels gets me similar coverage for the lowest level and a shot at the upper levels. It feels like the right tradeoff of effort for chance, but I don't have an analysis to back that up.

William