Information for cow-orkers

Please report any factorizations you find to me by email and inform me of which algorithm you used to find them. Additional information is also welcome: this may include NFS polynomials, factor base and large prime bounds and the size of the matrix or, for ECM, the number of curves run and the B1, B2 and sigma values for the successful curve. Most if not all of this information can be cut and pasted from the output of the factoring software used.

These are the ten Most Wanted Numbers

2,701+ C185
2,951- C290
3,464- C225
3,471+ C150
4,384- C234
5,299- C191
5,300+ C194
6,293+ C231
10,208- C178
12,210+ C150

The first five holes in each table are

2,705- 2,706- 2,707- 2,708- 2,710- 
2,701+ 2,707+ 2,708+ 2,709+ 2,714+ 
3,436- 3,446- 3,447- 3,450- 3,451- 
3,437+ 3,438+ 3,443+ 3,451+ 3,458+ 
4,351- 4,353- 4,354- 4,355- 4,358- 
4,347+ 4,354+ 4,356+ 4,358+ 4,362+ 
5,299- 5,301- 5,303- 5,305- 5,306- 
5,300+ 5,302+ 5,303+ 5,304+ 5,305+ 
6,270- 6,273- 6,274- 6,278- 6,279- 
6,269+ 6,270+ 6,273+ 6,279+ 6,280+ 
7,265- 7,266- 7,269- 7,270- 7,273- 
7,252+ 7,258+ 7,261+ 7,263+ 7,264+ 
8,231- 8,240- 8,241- 8,242- 8,245- 
8,235+ 8,239+ 8,241+ 8,242+ 8,245+ 
9,221- 9,227- 9,229- 9,230- 9,232- 
9,221+ 9,222+ 9,225+ 9,228+ 9,230+ 
10,208- 10,214- 10,219- 10,221- 10,223- 
10,211+ 10,213+ 10,214+ 10,218+ 10,227+ 
11,201- 11,210- 11,213- 11,215- 11,217- 
11,203+ 11,204+ 11,211+ 11,212+ 11,213+ 
12,201- 12,203- 12,207- 12,209- 12,211- 
12,201+ 12,202+ 12,203+ 12,205+ 12,206+ 

The smallest composite remaining to be factored has 150 digits. There are 32 composites with fewer than 160 digits and 99 with at least 1000 digits.

For those wishing to factor with the SNFS algorithm, this table contains the a and n values sorted by SNFS-difficulty (defined here as log10 (n.an) ) for those unfactored numbers which have SNFS-difficulty under 220. There are 81 entries in this table, some of which may have been reserved.

The ECMNet server running at 83.217:167.177:8194 is now loaded with the GCW composites which have at least 300 digits. The others are now available for independent work. Please note that this server is still version 2.x and does not work with V3.0 clients.

The following numbers have been reserved. They have been removed from the ECMNet server. Please mail me if you would like to reserve some numbers for yourself.

Number Size Reserved by Date
8,266- C243 Phil Frakes 2013-04-21
2,701+ C185 Jo Yeong Uk 2013-04-28
3,584+ C160 Phil Frakes 2013-05-13
2,741- C150 Paul Leyland 2013-05-14
5,375- C150 Paul Leyland 2013-05-14
11,203+ C207 Paul Leyland 2013-05-18