List of champions for factoring Cunningham numbers: Quadratic sieve method: 4564 C124 2,895- Jens Franke 4535 C124 2,1526M Jens Franke Special number field sieve by size of number factored: 4530 C227 2,773+ The Cabal 4342 C211 10,211- The Cabal Special number field sieve by SNFS difficulty: 4530 C227 2,773+ The Cabal 4342 C211 10,211- The Cabal 4527 C190 10,194+ R. Silverman + CWI 4491 C156 10,191+ R. Silverman + CWI General number field sieve by size of number factored: 4559 C142 2,779- B. Dodson + CWI + A. K. Lenstra + Edick + P. Leyland 4447 C141 10,212+ A. K. Lenstra + B. Dodson + F. Morain + CWI 4540 C137 2,688+ A. K. Lenstra + B. Dodson + Edick + CWI First five holes in each table on March 18, 2001 2,641- c148 2,643- c188 2,671- c145 2,673- c151 2,683- c203 2,617+ c170 2,619+ c186 2,631+ c144 2,641+ c169 2,647+ c169 2,1202L c178 2,1222L c161 2,1234M c144 2,1238L c160 2,1238M c145 2,632+ c177 2,716+ c163 2,736+ c172 2,760+ c153 2,764+ c220 3,379- c155 3,389- c168 3,397- c178 3,431- c198 3,437- c151 3,382+ c168 3,386+ c158 3,397+ c162 3,404+ c141 3,409+ c161 5,307- c187 5,311- c173 5,313- c210 5,317- c194 5,319- c182 5,283+ c168 5,284+ c152 5,289+ c156 5,298+ c189 5,301+ c149 6,251- c157 6,257- c173 6,259- c159 6,263- c196 6,277- c185 6,232+ c175 6,233+ c175 6,241+ c184 6,242+ c141 6,244+ c178 7,227- c192 7,233- c155 7,253- c177 7,257- c192 7,259- c175 7,214+ c150 7,232+ c171 7,233+ c150 7,239+ c176 7,253+ c164 10,223- c211 10,227- c212 10,233- c162 10,239- c228 10,241- c229 10,223+ c201 10,226+ c197 10,229+ c164 10,232+ c205 10,233+ c207 11,191- c193 11,199- c173 11,217- c171 11,221- c135 11,227- c195 11,181+ c155 11,188+ c184 11,197+ c205 11,206+ c213 11,208+ c185 12,173- c152 12,179- c190 12,193- c199 12,197- c212 12,199- c146 12,172+ c169 12,173+ c171 12,178+ c145 12,202+ c216 12,203+ c182 Smaller but Needed Numbers: 11,237+ c115 being done by Franke (see # 4569) 2,1462M c130 11,407M c130 5,685M c131