Contribution and Reservation

(5·10²⁰⁰-11)/3 =: 1(6)₁₉₉3_<201>; = 1613 · 60077 · [1719911675105464897921883352267324991066864755085970593438633962491127362648257805321223036209407130519209034773081372051833611080149834439754233840354007631378815730255767411638497144893302063_<193>] SUBMIT/RESERVE

Status

Expression:	(5·10²⁰⁰-11)/3
Composite Factor:	171991167510546489792188335226732499106686475508597059343863 396249112736264825780532122303620940713051920903477308137205 183361108014983443975423384035400763137881573025576741163849 7144893302063 (193-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 200.70-digit and the GNFS difficulty is 192.24-digit. SNFS must be faster than GNFS. It will take about 20 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 16663_200.
Put the following polynomial file 16663_200.poly in there too.
And then, run "perl factMsieve.pl 16663_200".

16663_200.poly ^*1

n: 1719911675105464897921883352267324991066864755085970593438633962491127362648257805321223036209407130519209034773081372051833611080149834439754233840354007631378815730255767411638497144893302063
m: 10000000000000000000000000000000000000000
deg: 5
c5: 5
c0: -11
skew: 1.17
type: snfs
lss: 1
rlim: 15500000
alim: 15500000
lpbr: 29
lpba: 29
mfbr: 56
mfba: 56
rlambda: 2.6
alambda: 2.6

*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 193-digit composite number so far are as follows. According to the reports, unknown prime factors of this composite number are probably 30-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
30	25e4	430	Makoto Kamada	Apr 10, 2008
30	25e4	430 / 430
35	1e6	0 / 825
35	1e6	/ 825
40	3e6	0 / 2336 (294)
40	3e6	/ 2336 (294)
45	11e6	0 / 4479 (677)
45	11e6	/ 4479 (677)
50	43e6	0 / 7553 (1277)
50	43e6	/ 7553 (1277)

Command line to find prime factors up to about 35-digit

echo 1719911675105464897921883352267324991066864755085970593438633962491127362648257805321223036209407130519209034773081372051833611080149834439754233840354007631378815730255767411638497144893302063 | ecm -n -c 825 1e6

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

echo 1719911675105464897921883352267324991066864755085970593438633962491127362648257805321223036209407130519209034773081372051833611080149834439754233840354007631378815730255767411638497144893302063 | ecm -n -c 2336 3e6

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

echo 1719911675105464897921883352267324991066864755085970593438633962491127362648257805321223036209407130519209034773081372051833611080149834439754233840354007631378815730255767411638497144893302063 | ecm -n -c 4479 11e6

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

echo 1719911675105464897921883352267324991066864755085970593438633962491127362648257805321223036209407130519209034773081372051833611080149834439754233840354007631378815730255767411638497144893302063 | ecm -n -c 7553 43e6

Submit factors

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