238 237 Exponent Status

PrimeNet Exponent Status

M_n

Status

Details

Composite: proven not-prime with Lucas-Lehmer test

No factors below 2⁶⁷

TF target 2⁴⁴

TF below 2^114 is very unlikely to find new factors due to ECM effort.

P-1

B1 =	126000000
B2 =	5214552833490

ECM

Estimated T-Level: 35.7 ⓘ

Status	Date	User	Residue	Shift
Verified		David Slowinski	76C9	0
Verified		Unknown	76C9	0
Verified		Brian J. Beesley	446CDABF820976C9	0
Verified		Eivind Triel	446CDABF820976C9	78780
Verified	2001-09-16	Brian J. Beesley	446CDABF820976C9	181255

History

Date	User	Type	Result
2025-06-14	tim s	NF	no factor from 2^66 to 2^67
2023-02-11	masser	NF-PP1	Start=6/5, B1=30000000, B2=990000000
2023-02-05	masser	NF-PP1	Start=2/7, B1=30000000, B2=990000000
2023-02-05	masser	NF-PP1	Start=186/37, B1=30000000, B2=960000000
2022-06-03	Sid & Andy	NF-PM1	B1=126000000, B2=5214552833490
2022-03-07	LordJulius	NF	no factor from 2^54 to 2^55
2019-12-29	Gordon Spence	NF	no factor from 2^65 to 2^66
2019-04-07	alex	NF-PM1	B1=100000000, B2=2000000000, E=12
2018-03-09	Gordon Spence	NF	no factor from 2^64 to 2^65
2016-05-13	Numberwang	NF-PM1	B1=2664, B2=66600
2016-02-23	Mark Rose	NF	no factor from 2^57 to 2^58
2016-01-12	Gordon Spence	NF	no factor from 2^63 to 2^64
2016-01-12	Gordon Spence	NF	no factor from 2^62 to 2^63
2015-07-24	snme2pm1	NF	no factor from 2^61 to 2^62
2014-12-15	Denial140	NF-PM1	B1=10000000, B2=250000000, E=12
2013-10-11	David Campeau	NF-PM1	B1=2690000, B2=78010000, E=12
2013-07-21	lycorn	NF	no factor from 2^60 to 2^61
2012-02-26	Joss	NF-PM1	B1=2667533
2011-07-24	Joss	NF-PM1	B1=2134026
2011-02-01	Joss	NF-PM1	B1=2000000
2009-01-23	Sturle Sunde	NF	no factor from 2^59 to 2^60
2008-12-31	Sturle Sunde	NF	no factor from 2^58 to 2^59

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