Contribution and Reservation

10²³¹-9 =: (9)₂₃₀1_<231>; = 919 · 227947037 · 237397921 · [20108219899963991178385032945756915630579944870602241047661356606913124250453411138118595381885232035113915967840276407154028434896573735056433545137633205791188008513050065381806144502965904984700952873258485557_<212>] SUBMIT/RESERVE

Status

Expression:	10²³¹-9
Composite Factor:	201082198999639911783850329457569156305799448706022410476613 566069131242504534111381185953818852320351139159678402764071 540284348965737350564335451376332057911880085130500653818061 44502965904984700952873258485557 (212-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 231.90-digit and the GNFS difficulty is 211.30-digit. SNFS must be faster than GNFS. It will take about 224 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 99991_231.
Put the following polynomial file 99991_231.poly in there too.
And then, run "perl factMsieve.pl 99991_231".

99991_231.poly ^*1

n: 20108219899963991178385032945756915630579944870602241047661356606913124250453411138118595381885232035113915967840276407154028434896573735056433545137633205791188008513050065381806144502965904984700952873258485557
m: 200000000000000000000000000000000000000
deg: 6
c6: 125
c0: -72
skew: 0.91
type: snfs
lss: 1
rlim: 51000000
alim: 51000000
lpbr: 30
lpba: 30
mfbr: 59
mfba: 59
rlambda: 2.7
alambda: 2.7

*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 212-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	0 / 0
45	11e6	713	Dmitry Domanov	Jun 30, 2009
		713 / 4479
		/ 3766
50	43e6	0 / 7393 (1074)
50	43e6	/ 7393 (1074)
55	11e7	0 / 17725 (3067)
55	11e7	/ 17725 (3067)
60	26e7	0 / 42006 (7624)
60	26e7	/ 42006 (7624)

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

echo 20108219899963991178385032945756915630579944870602241047661356606913124250453411138118595381885232035113915967840276407154028434896573735056433545137633205791188008513050065381806144502965904984700952873258485557 | ecm -n -c 3766 11e6

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

echo 20108219899963991178385032945756915630579944870602241047661356606913124250453411138118595381885232035113915967840276407154028434896573735056433545137633205791188008513050065381806144502965904984700952873258485557 | ecm -n -c 7393 43e6

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

echo 20108219899963991178385032945756915630579944870602241047661356606913124250453411138118595381885232035113915967840276407154028434896573735056433545137633205791188008513050065381806144502965904984700952873258485557 | ecm -n -c 17725 11e7

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

echo 20108219899963991178385032945756915630579944870602241047661356606913124250453411138118595381885232035113915967840276407154028434896573735056433545137633205791188008513050065381806144502965904984700952873258485557 | ecm -n -c 42006 26e7

Submit factors

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