Date: Mon, 28 Dec 2009 21:16:31 +0100
From: yoyo
To: Paul Zimmermann
Subject: found gmp-ecm top50 factor
Content-Type: text/plain; charset=ISO-8859-1
Hello Paul,
one of my Boinc users found this factor. It is for this NearRepdigit
number http://hpcgi2.nifty.com/m_kamada/f/c.cgi?q=71111_341
GMP-ECM 6.2.3 [powered by GMP 4.2.1_MPIR_1.1.1] [ECM]
Input number is 77408690560905323438604044124883251342679827896247009602906199773873214100553786332237393178163861313602627195323510786443486054674798080254490528322806462692451464212829574207211148953372274886526030715252104152499523855481315533280604274379459295999774273361676468956372168684508022110729619071 (296 digits)
[Mon Dec 28 17:52:39 2009]
Using MODMULN
Using B1=110000000, B2=776278396540, polynomial Dickson(30), sigma=1998958586 (g1=723922811009, not found by ecm2)
dF=131072, k=4, d=1345890, d2=11, i0=71
Expected number of curves to find a factor of n digits:
20 25 30 35 40 45 50 55 60 65
2 4 10 34 135 613 3133 17769 111196 751771
Step 1 took 1313688ms
Using 35 small primes for NTT
Estimated memory usage: 786M
Initializing tables of differences for F took 828ms
Computing roots of F took 43531ms
Building F from its roots took 30688ms
Computing 1/F took 14093ms
Initializing table of differences for G took 687ms
Computing roots of G took 37485ms
Building G from its roots took 27015ms
Computing roots of G took 37391ms
Building G from its roots took 26969ms
Computing G * H took 7797ms
Reducing G * H mod F took 7516ms
Computing roots of G took 37343ms
Building G from its roots took 27157ms
Computing G * H took 7672ms
Reducing G * H mod F took 7438ms
Computing roots of G took 37172ms
Building G from its roots took 26968ms
Computing G * H took 7719ms
Reducing G * H mod F took 7422ms
Computing polyeval(F,G) took 53688ms
Computing product of all F(g_i) took 234ms
Step 2 took 447890ms
********** Factor found in step 2: 42593783346150223186979443437882164324892008462850480008134130873603
Found probable prime factor of 68 digits: 42593783346150223186979443437882164324892008462850480008134130873603
Probable prime cofactor 1817370622652185573516449780262960978136126707676421865776098840020502976296133704522386290554612631491430633210965174386930308114306076739417849044953074641365372499555249805775538554420955061583147505660366237473218561112127957 has 229 digits
Report your potential champion to Richard Brent
(see http://wwwmaths.anu.edu.au/~brent/ftp/champs.txt)