Contribution and Reservation

(64·10²⁹⁵-1)/9 =: 7(1)₂₉₅_<296>; = 138283 · 215123 · 27821253425770631779688809196979341911471_<41> · [85922149607726026782156764348422317355098680473279943458089419000214805543256458905381333491902976675767807884711080103009541396355333130708765008447187044809202021290263519849408848513151067396999960418817775487954720426652016355985801204889849_<245>] (Lionel Debroux / GMP-ECM 6.2.3 B1=110000000, sigma=3203913405 for P41 / Nov 25, 2009) SUBMIT/RESERVE

Status

Expression:	(64·10²⁹⁵-1)/9
Composite Factor:	859221496077260267821567643484223173550986804732799434580894 190002148055432564589053813334919029766757678078847110801030 095413963553331307087650084471870448092020212902635198494088 485131510673969999604188177754879547204266520163559858012048 89849 (245-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 296.81-digit and the GNFS difficulty is 244.93-digit. SNFS must be faster than GNFS. It will take about 32608 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 71111_295.
Put the following polynomial file 71111_295.poly in there too.
And then, run "perl factMsieve.pl 71111_295".

71111_295.poly ^*1

n: 85922149607726026782156764348422317355098680473279943458089419000214805543256458905381333491902976675767807884711080103009541396355333130708765008447187044809202021290263519849408848513151067396999960418817775487954720426652016355985801204889849
m: 20000000000000000000000000000000000000000000000000
deg: 6
c6: 10
c0: -1
skew: 0.68
type: snfs
lss: 1
rlim: 620000000
alim: 620000000
lpbr: 32
lpba: 32
mfbr: 68
mfba: 68
rlambda: 2.9
alambda: 2.9

*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 245-digit composite number so far are as follows. According to the reports, unknown prime factors of this composite number are probably 45-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
45	11e6	120	Serge Batalov	Jan 25, 2009
		400	Serge Batalov	Jan 27, 2009
		26	Andreas Tete	Apr 10, 2009
		4000	Markus Tervooren	Apr 20, 2009
		4546 / 3622
50	43e6	170	Serge Batalov	Aug 20, 2009
		170 / 6477
		/ 6307
55	11e7	10	Lionel Debroux	Nov 24, 2009
		10 / 17418 (2626)
		/ 17408 (2616)
60	26e7	0 / 41921 (7488)
60	26e7	/ 41921 (7488)
65	85e7	0 / 69392 (13580)
65	85e7	/ 69392 (13580)

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

echo 85922149607726026782156764348422317355098680473279943458089419000214805543256458905381333491902976675767807884711080103009541396355333130708765008447187044809202021290263519849408848513151067396999960418817775487954720426652016355985801204889849 | ecm -n -c 6307 43e6

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

echo 85922149607726026782156764348422317355098680473279943458089419000214805543256458905381333491902976675767807884711080103009541396355333130708765008447187044809202021290263519849408848513151067396999960418817775487954720426652016355985801204889849 | ecm -n -c 17408 11e7

Command line to find prime factors up to about 60-digit

echo 85922149607726026782156764348422317355098680473279943458089419000214805543256458905381333491902976675767807884711080103009541396355333130708765008447187044809202021290263519849408848513151067396999960418817775487954720426652016355985801204889849 | ecm -n -c 41921 26e7

Command line to find prime factors up to about 65-digit

echo 85922149607726026782156764348422317355098680473279943458089419000214805543256458905381333491902976675767807884711080103009541396355333130708765008447187044809202021290263519849408848513151067396999960418817775487954720426652016355985801204889849 | ecm -n -c 69392 85e7

Submit factors

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