123 143 Exponent Status

PrimeNet Exponent Status

M_n

Status

Details

Composite: proven not-prime with Lucas-Lehmer test

No factors below 2⁶⁸

TF target 2⁴⁴

TF below 2^115 is very unlikely to find new factors due to ECM effort.

P-1

B1 =	10000000000
B2 =	756670016752650

ECM

Estimated T-Level: 36.0 ⓘ

Status	Date	User	Residue	Shift
Verified		Unknown	5408	0
Verified		Jay R. Hill	345AA18FA0745408	0
Verified		Brian J. Beesley	345AA18FA0745408	0
Verified		Eivind Triel	345AA18FA0745408	92820
Verified	2016-06-01	MadPoo	345AA18FA0745408	66074

Assigned

Assigned	User	Work Type	Updated
2025-08-28	-Anonymous-	factor ECM small	2025-08-28
2025-08-28	-Anonymous-	factor ECM small	2025-08-28
2025-08-07	-Anonymous-	factor ECM small	2025-08-07

History

Date	User	Type	Result
2023-09-06	masser	NF-PP1	Start=6/5, B1=50000000, B2=3950000000
2023-08-31	masser	NF-PP1	Start=165/29, B1=50000000, B2=3950000000
2023-08-03	Oliver Kruse	NF-PM1	B1=10000000000, B2=756670016752650
2023-04-29	masser	NF-PP1	Start=177/41, B1=50000000, B2=2550000000
2023-04-24	masser	NF-PP1	Start=2/7, B1=50000000, B2=4050000000
2023-02-17	Joss	NF-PM1	B1=1000000, B2=522803591310
2023-01-13	Joss	NF-PM1	B1=1000000, B2=173706132600
2022-04-26	404_factor_not_found	NF	no factor from 2^67 to 2^68
2022-03-07	LordJulius	NF	no factor from 2^54 to 2^55
2020-02-08	Gordon Spence	NF	no factor from 2^66 to 2^67
2019-07-05	Yxinity	NF	no factor from 2^65 to 2^66
2018-05-10	chuenkit	NF	no factor from 2^64 to 2^65
2016-06-01	MadPoo	C-LL	345AA18FA0745408
2016-02-23	Mark Rose	NF	no factor from 2^57 to 2^58
2016-02-22	Gordon Spence	NF	no factor from 2^63 to 2^64
2016-02-22	Gordon Spence	NF	no factor from 2^62 to 2^63
2015-08-13	NR	NF	no factor from 2^61 to 2^62
2013-09-23	Sid & Andy	NF	no factor from 2^60 to 2^61
2013-02-07	alpertron	NF-PM1	B1=100000000, B2=2000000000, E=12
2009-01-28	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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