Contribution and Reservation

(14·10²⁰³-17)/3 =: 4(6)₂₀₂1_<204>; = 13 · 71 · [505597688696280245576020223907547851209823040808956301914048392921632358252076561935716865294330083062477428674611773203322499097146984470928132899963885879378837125315998555435175153485012639942217407_<201>] SUBMIT/RESERVE

Status

Expression:	(14·10²⁰³-17)/3
Composite Factor:	505597688696280245576020223907547851209823040808956301914048 392921632358252076561935716865294330083062477428674611773203 322499097146984470928132899963885879378837125315998555435175 153485012639942217407 (201-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 205.54-digit and the GNFS difficulty is 200.70-digit. SNFS must be faster than GNFS. It will take about 30 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 46661_203.
Put the following polynomial file 46661_203.poly in there too.
And then, run "perl factMsieve.pl 46661_203".

46661_203.poly ^*1

n: 505597688696280245576020223907547851209823040808956301914048392921632358252076561935716865294330083062477428674611773203322499097146984470928132899963885879378837125315998555435175153485012639942217407
m: 50000000000000000000000000000000000000000
deg: 5
c5: 112
c0: -425
skew: 1.31
type: snfs
lss: 1
rlim: 18700000
alim: 18700000
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 201-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	0 / 0
40	3e6	300	Serge Batalov	Feb 17, 2009
		300 / 2336
		/ 2036
45	11e6	0 / 4413 (590)
45	11e6	/ 4413 (590)
50	43e6	0 / 7542 (1258)
50	43e6	/ 7542 (1258)
55	11e7	0 / 17767 (3129)
55	11e7	/ 17767 (3129)

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

echo 505597688696280245576020223907547851209823040808956301914048392921632358252076561935716865294330083062477428674611773203322499097146984470928132899963885879378837125315998555435175153485012639942217407 | ecm -n -c 2036 3e6

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

echo 505597688696280245576020223907547851209823040808956301914048392921632358252076561935716865294330083062477428674611773203322499097146984470928132899963885879378837125315998555435175153485012639942217407 | ecm -n -c 4413 11e6

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

echo 505597688696280245576020223907547851209823040808956301914048392921632358252076561935716865294330083062477428674611773203322499097146984470928132899963885879378837125315998555435175153485012639942217407 | ecm -n -c 7542 43e6

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

echo 505597688696280245576020223907547851209823040808956301914048392921632358252076561935716865294330083062477428674611773203322499097146984470928132899963885879378837125315998555435175153485012639942217407 | ecm -n -c 17767 11e7

Submit factors

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