245 251 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 2^103 is very unlikely to find new factors due to ECM effort.

P-1

B1 =	122000000
B2 =	5021421284880

ECM

Estimated T-Level: 32.6 ⓘ

Status	Date	User	Residue	Shift
Verified		David Slowinski	5F2	0
Verified		Unknown	05F2	0
Verified		Ken Kiefer	F82516A42B5005F2	0
Verified		Brian J. Beesley	F82516A42B5005F2	0
Verified		Eivind Triel	F82516A42B5005F2	171388
Verified	2016-06-01	MadPoo	F82516A42B5005F2	244324

History

Date	User	Type	Result
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=137/47, B1=30000000, B2=960000000
2022-06-02	Sid & Andy	NF-PM1	B1=122000000, B2=5021421284880
2022-03-07	LordJulius	NF	no factor from 2^54 to 2^55
2019-12-30	Gordon Spence	NF	no factor from 2^65 to 2^66
2019-04-13	alex	NF-PM1	B1=100000000, B2=2000000000, E=12
2018-03-11	Gordon Spence	NF	no factor from 2^64 to 2^65
2016-06-01	MadPoo	C-LL	F82516A42B5005F2
2016-05-13	Numberwang	NF-PM1	B1=2742, B2=68550
2016-02-23	Mark Rose	NF	no factor from 2^57 to 2^58
2016-01-21	Gordon Spence	NF	no factor from 2^63 to 2^64
2016-01-21	Gordon Spence	NF	no factor from 2^62 to 2^63
2015-08-04	snme2pm1	NF	no factor from 2^61 to 2^62
2014-12-18	Denial140	NF-PM1	B1=10000000, B2=250000000, E=12
2013-10-12	David Campeau	NF-PM1	B1=2610000, B2=75690000, E=12
2013-07-15	lycorn	NF	no factor from 2^60 to 2^61
2012-02-26	Joss	NF-PM1	B1=2569038
2011-07-24	Joss	NF-PM1	B1=2055231
2011-02-04	Joss	NF-PM1	B1=2000000
2009-01-24	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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