267 199 Exponent Status

PrimeNet Exponent Status

M_n

Status

Details

Composite: proven not-prime with Lucas-Lehmer test

No factors below 2⁶⁶

TF target 2⁴⁴

TF below 2^101 is very unlikely to find new factors due to ECM effort.

P-1

B1 =	242000000
B2 =	2479832590950

ECM

Estimated T-Level: 32.0 ⓘ

Status	Date	User	Residue	Shift
Verified		David Slowinski	4FD7	0
Verified		Unknown	4FD7	0
Verified		Brian J. Beesley	ACC7EFAD181C4FD7	0
Verified		Eivind Triel	ACC7EFAD181C4FD7	73290
Verified	2001-10-27	Brian J. Beesley	ACC7EFAD181C4FD7	55029

Assigned

Assigned	User	Work Type	Updated
2025-10-07	-Anonymous-	factor ECM small	2025-10-07
2025-10-05	-Anonymous-	factor ECM small	2025-10-05
2025-10-05	-Anonymous-	factor ECM small	2025-10-05
2025-10-05	-Anonymous-	factor ECM small	2025-10-05
2025-10-04	-Anonymous-	factor ECM small	2025-10-04
2025-08-20	-Anonymous-	factor ECM small	2025-08-21
2025-08-16	-Anonymous-	factor ECM small	2025-08-16

History

Date	User	Type	Result
2023-09-04	masser	NF-PP1	Start=159/53, B1=20000000, B2=1580000000
2023-09-03	masser	NF-PP1	Start=6/5, B1=20000000, B2=1580000000
2022-06-20	Sid & Andy	NF-PM1	B1=242000000, B2=2479832590950
2022-03-07	LordJulius	NF	no factor from 2^54 to 2^55
2021-07-03	George Woltman	NF-PP1	Start=2/7, B1=50000000, B2=4850000000
2020-01-03	Gordon Spence	NF	no factor from 2^65 to 2^66
2019-04-22	alex	NF-PM1	B1=100000000, B2=2000000000, E=12
2018-03-20	Gordon Spence	NF	no factor from 2^64 to 2^65
2016-08-23	Joss	NF-PM1	B1=10700000, B2=940637920, E=12
2016-04-15	Joss	NF-PM1	B1=10700000, B2=470318960, E=12
2016-03-29	Joss	NF-PM1	B1=5885000
2016-02-23	Mark Rose	NF	no factor from 2^57 to 2^58
2015-12-07	Gordon Spence	NF	no factor from 2^63 to 2^64
2015-12-07	Gordon Spence	NF	no factor from 2^62 to 2^63
2015-08-25	NR	NF	no factor from 2^61 to 2^62
2013-08-27	David Campeau	NF-PM1	B1=5350000, B2=192600000, E=12
2013-07-09	lycorn	NF	no factor from 2^60 to 2^61
2012-02-26	Joss	NF-PM1	B1=2298825
2011-02-16	Joss	NF-PM1	B1=2000000
2009-01-25	Sturle Sunde	NF	no factor from 2^59 to 2^60
2009-01-01	Sturle Sunde	NF	no factor from 2^58 to 2^59

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