In January 1999, while preparing some work for his students, he identified a highly structured prime number with exactly two thousand digits.
In July 1999 - while a participant in the Proth Search Group - he became the discoverer of the then-largest known composite Fermat number,[REF] a record which his St. Patrick's College (Drumcondra) based Proth-Gallot Group twice broke in 2003, the 1999 record having stood until then [REF].