Thank you all for your answers (Chris, Bryan, Conrad and George) Patrick -------- Original Message -------- De: Patrick Fossano - OCISI <[EMAIL PROTECTED]> Objet: Proth Numbers A: _Liste Mersenne <[EMAIL PROTECTED]> Hi. Does someone know if "k" and "n" should be of a particular type (even/odd, or n=4kp+3q! or what else...) for 1 + k.2^n to be a good prime candidate? Thank you, Patrick _________________________________________________________________ Unsubscribe & list info -- http://www.scruz.net/~luke/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers