List of recent champions for factoring Cunningham numbers: Special number field sieve by size of number factored: 4757 C244 2,809- Franke/Kleinjung/Bahr/CWI 4703 C227 2,751- CWI/Dodson/Franke/AKL/Leyland Special number field sieve by SNFS difficulty: 4757 C244 2,809- Franke/Kleinjung/Bahr/CWI 4703 C227 2,751- CWI/Dodson/Franke/AKL/Leyland General number field sieve by size of number factored: 4701 C158 2,953+ F. Bahr + J. Franke + T. Kleinjung 4559 C142 2,779- B. Dodson + CWI + A. K. Lenstra + Edick + P. Leyland Elliptic curve method: 4830 P57 2,997- B. Dodson ECMNET 4253 P53 2,677- C. Curry ECMNET 4827 P52 2,773- P. Johansson ECMNET Largest penultimate prime factor (ultimate factor shown also): 4677 p98*p128 2,727- Dodson/AKL/CWI 4342 p93*p118 10,211- The Cabal First five holes in each table on June 25, 2003 2,713- c171 2,731- c183 2,739- c168 2,743- c151 2,757- c213 2,653+ c154 2,659+ c188 2,661+ c148 2,667+ c161 2,671+ c165 2,1238L c160 2,1238M c145 2,1262L c177 2,1262M c178 2,1294L c187 2,716+ c163 2,736+ c172 2,760+ c153 2,764+ c220 2,772+ c215 3,431- c198 3,437- c151 3,443- c187 3,449- c175 3,451- c167 3,409+ c161 3,412+ c195 3,419+ c173 3,424+ c156 3,436+ c194 5,307- c187 5,311- c173 5,313- c210 5,317- c194 5,319- c182 5,302+ c187 5,304+ c172 5,307+ c159 5,311+ c203 5,313+ c197 6,263- c196 6,277- c139 6,281- c162 6,283- c173 6,293- c214 6,251+ c179 6,257+ c200 6,263+ c186 6,268+ c138 6,269+ c135 7,253- c177 7,257- c192 7,259- c175 7,263- c161 7,269- c224 7,232+ c171 7,233+ c150 7,239+ c176 7,253+ c164 7,254+ c178 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 10,236+ c193 11,199- c173 11,217- c171 11,221- c135 11,227- c195 11,229- c217 11,206+ c213 11,208+ c185 11,212+ c201 11,218+ c192 11,220+ c147 12,193- c199 12,199- c146 12,215- c182 12,227- c197 12,229- c242 12,202+ c216 12,206+ c192 12,208+ c202 12,209+ c185 12,214+ c189