Contribution and Reservation

(43·10²⁴⁸-7)/9 =: 4(7)₂₄₈_<249>; = 3 · 2650409 · [60088559637119878199651170539814518913593811090763447927945935611922257756919501578533448708957470058115279286804134478587742216110517002945303633989795257735413386861899148116105574369563059610520209997498219806550332140910802543780699227651_<242>] SUBMIT/RESERVE

Status

Expression:	(43·10²⁴⁸-7)/9
Composite Factor:	600885596371198781996511705398145189135938110907634479279459 356119222577569195015785334487089574700581152792868041344785 877422161105170029453036339897952577354133868618991481161055 743695630596105202099974982198065503321409108025437806992276 51 (242-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 250.84-digit and the GNFS difficulty is 241.78-digit. SNFS must be faster than GNFS. It will take about 957 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 47777_248.
Put the following polynomial file 47777_248.poly in there too.
And then, run "perl factMsieve.pl 47777_248".

47777_248.poly ^*1

n: 60088559637119878199651170539814518913593811090763447927945935611922257756919501578533448708957470058115279286804134478587742216110517002945303633989795257735413386861899148116105574369563059610520209997498219806550332140910802543780699227651
m: 200000000000000000000000000000000000000000
deg: 6
c6: 1075
c0: -112
skew: 0.69
type: snfs
lss: 1
rlim: 106000000
alim: 106000000
lpbr: 31
lpba: 31
mfbr: 62
mfba: 62
rlambda: 2.8
alambda: 2.8

*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 242-digit composite number so far are as follows. According to the reports, unknown prime factors of this composite number are probably 40-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
40	3e6	800	Serge Batalov	Jan 29, 2009
		432	Serge Batalov	Aug 19, 2009
		1232 / 1232
45	11e6	320	Serge Batalov	Jan 29, 2009
		320 / 4207
		/ 3887
50	43e6	0 / 7435 (1108)
50	43e6	/ 7435 (1108)
55	11e7	0 / 17740 (3084)
55	11e7	/ 17740 (3084)
60	26e7	0 / 42011 (7631)
60	26e7	/ 42011 (7631)

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

echo 60088559637119878199651170539814518913593811090763447927945935611922257756919501578533448708957470058115279286804134478587742216110517002945303633989795257735413386861899148116105574369563059610520209997498219806550332140910802543780699227651 | ecm -n -c 3887 11e6

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

echo 60088559637119878199651170539814518913593811090763447927945935611922257756919501578533448708957470058115279286804134478587742216110517002945303633989795257735413386861899148116105574369563059610520209997498219806550332140910802543780699227651 | ecm -n -c 7435 43e6

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

echo 60088559637119878199651170539814518913593811090763447927945935611922257756919501578533448708957470058115279286804134478587742216110517002945303633989795257735413386861899148116105574369563059610520209997498219806550332140910802543780699227651 | ecm -n -c 17740 11e7

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

echo 60088559637119878199651170539814518913593811090763447927945935611922257756919501578533448708957470058115279286804134478587742216110517002945303633989795257735413386861899148116105574369563059610520209997498219806550332140910802543780699227651 | ecm -n -c 42011 26e7

Submit factors

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