Contribution and Reservation

(19·10¹⁹⁵-7)/3 =: 6(3)₁₉₄1_<196>; = 13 · 1637 · [297605062418745986247513431386369688141221433829863884842504268283132058330592234074213304512632551728458875679401030653321429130836583493883432796077878545807684475980138777939633162602008051_<192>] SUBMIT/RESERVE

Status

Expression:	(19·10¹⁹⁵-7)/3
Composite Factor:	297605062418745986247513431386369688141221433829863884842504 268283132058330592234074213304512632551728458875679401030653 321429130836583493883432796077878545807684475980138777939633 162602008051 (192-digit)
Status:	Not factored. Not reserved. You can submit its factors or reserve it for submitting in the future.

How to factor it

ECM, P-1, P+1

Look for prime factors by GMP-ECM first. Refer to the section "Efforts by ECM". Not only ECM but also P-1/P+1 may be helpful.

SNFS

Use GGNFS and/or Msieve if GMP-ECM cannot find a factor. The SNFS difficulty of this composite number is 196.28-digit and the GNFS difficulty is 191.47-digit. SNFS must be faster than GNFS. It will take about 15 CPU-days to factor this composite number on 64-bit Opteron-2600MHz.

Put factMsieve.pl to which $GGNFS_BIN_PATH and $NUM_CPUS were modified properly in the working directory 63331_195.
Put the following polynomial file 63331_195.poly in there too.
And then, run "perl factMsieve.pl 63331_195".

63331_195.poly ^*1

n: 297605062418745986247513431386369688141221433829863884842504268283132058330592234074213304512632551728458875679401030653321429130836583493883432796077878545807684475980138777939633162602008051
m: 1000000000000000000000000000000000000000
deg: 5
c5: 19
c0: -7
skew: 0.82
type: snfs
lss: 1
rlim: 13100000
alim: 13100000
lpbr: 28
lpba: 28
mfbr: 55
mfba: 55
rlambda: 2.5
alambda: 2.5

*1 These parameters were not fully adjusted. The approximate expressions which were used for making the parameters are: deg=expt<=105?4:expt<=210?5:6 or expt<=144?4:6; d=log10(c[deg])+deg*log10(m)[digits]; time=10^(d/30-4)[hours]; skew=|c0/c[deg]|^(1/deg); rlim=round(7*10^(d/60+3)); lpbr=floor(d/25+21); mfbr=floor(d/8+31); rlambda=floor(d/25+18)/10;

Efforts by ECM

The efforts by ECM to find small factors of this 192-digit composite number so far are as follows. According to the reports, unknown prime factors of this composite number are probably 35-digit or more. Please report your efforts by ECM. (Anonymous reports are not acceptable)

Level	B1	Reported runs Total / Required runs (Required runs for lower level)	Name
35	1e6	118	Makoto Kamada	May 28, 2009
		786	Wataru Sakai	Sep 5, 2009
		904 / 904
40	3e6	0 / 2104
40	3e6	/ 2104
45	11e6	0 / 4439 (610)
45	11e6	/ 4439 (610)
50	43e6	0 / 7548 (1266)
50	43e6	/ 7548 (1266)
55	11e7	0 / 17769 (3131)
55	11e7	/ 17769 (3131)

Command line to find prime factors up to about 40-digit

echo 297605062418745986247513431386369688141221433829863884842504268283132058330592234074213304512632551728458875679401030653321429130836583493883432796077878545807684475980138777939633162602008051 | ecm -n -c 2104 3e6

Command line to find prime factors up to about 45-digit

echo 297605062418745986247513431386369688141221433829863884842504268283132058330592234074213304512632551728458875679401030653321429130836583493883432796077878545807684475980138777939633162602008051 | ecm -n -c 4439 11e6

Command line to find prime factors up to about 50-digit

echo 297605062418745986247513431386369688141221433829863884842504268283132058330592234074213304512632551728458875679401030653321429130836583493883432796077878545807684475980138777939633162602008051 | ecm -n -c 7548 43e6

Command line to find prime factors up to about 55-digit

echo 297605062418745986247513431386369688141221433829863884842504268283132058330592234074213304512632551728458875679401030653321429130836583493883432796077878545807684475980138777939633162602008051 | ecm -n -c 17769 11e7

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