The ECMNET Project

8 Mar 2010: a new release candidate for ECM 6.3 is available. Please help us to test it, and report problems to ecm-discuss
6 Mar 2010: only two months after the new ECM record of 68 digits by yoyo@home, Bos, Kleinjung, Lenstra and Montgomery break the 70-digit barrier with an amazing new ECM record of 73 digits!!!
3 Feb 2010: Tapio Rajala found a 54-digit factor of F14, which had previously no known factor!!!
29 Dec 2009: a new update of the EECM paper is available, together with the accompanying code

Results so far. Here are the (up to) 10 largest factors found by ECM so far this year (see also the all-times all-ecm-programs top-50 table, and the gmp-ecm top ten from 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 ):

digits	factor	from	B1	sigma	date	who
73	1808422353177349564546512035512530001279481259854248860454348989451026887	2¹¹⁸¹-1	3e9	4000027779	06 Mar 2010	J. Bos, T. Kleinjung, A. Lenstra, P. Montgomery
63	153327833285998453874202767942570343649971393640068204571694369	2¹¹⁸⁷-1	3e9	3000000588	30 Jan 2010	J. Bos/T. Kleinjung
62	44098070546316336069732891124299479167253575131341897248372433	6³⁴⁴+1	260e6	3660690326	10 Feb 2010	B. Dodson
62	13055369049845151421562673963068310715129211918218895785368571	HP49(100)	260e6	1765817006	08 Feb 2010	N. Daminelli
61	2664797814058212286560533454960446792210016180875809243599817	2¹⁰⁸⁷-1	26e7	260005814	20 Feb 2010	J. Bos/T. Kleinjung
59	43976229065455869110045557754921993324851820720678681937281	687⁶⁴+1	11e6	2408138291	25 Jan 2010	T. Adachi
59	41120912566813018675472321435609728349473493582225344661873	2¹⁰¹³-1	26e7	263400010	03 Mar 2010	J. Bos/T. Kleinjung
58	5007861129737749849013925511829197666405121545507799101441	2¹¹⁹⁵+1	300e6	3011008	22 Feb 2010	A. Bhargava, S. Pelissier
58	2843789544342214765667723140574766627206951083329762210791	98¹²¹-1	300e6	7000308	15 Jan 2010	A. Bhargava, S. Pelissier
57	102182813843837387042630517407087819649934313882546476897	110⁶³ + 63¹¹⁰	43e6	1521428326	14 Jan 2010	yoyo@home/Jeff17

A(n,k): k-th term of aliquot sequence starting from n

ECMNET Newsletters: number 1 (13 Feb 1998), number 2 (15 Mar 1998), number 3 (17 Apr 1998), number 4 (15 May 1998), number 5 (18 June 1998), number 6 (15 July 1998), number 7 (17 August 1998), number 8 (17 September 1998), number 9 (16 October 1998), number 10 (23 November 1998), number 11 (17 December 1998), number 12 (19 April 1999), number 13 (16 December 1999).

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