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[QUOTE=swishzzz;346865]How do I find the group order for this factorization? factordb's group order calculator clearly fails for this one...[/QUOTE]
sigma 1:<something> is not a Brent-Suyama curve, and Factordb up to now only supports Brent-Suyama curves (sigma 0:<something>). Tried some Magma code, based on the GMP-ECM manual: (won't work, and I have no idea why) [code]FindGroupOrder := function (p, s) K := GF(p); A := K ! (4*s^2-2); x := 2; b := x^3 + A*x^2 + x; E := EllipticCurve([0,b*A,0,b^2,0]); return FactoredOrder(E); end function; p := 26759964491830480636236398774973830719679139755537527; s := 3576746370; FindGroupOrder(p,s);[/code] |
I've just got factorization of 102^103 + 1 = 103^2 * prp74 * prp130 with SNFS:
[code]prp74 factor: 16577923085747542727498881886756397313868752518022676502052070512564532587 prp130 factor: 4371325251720559422253332573045929417056159075217221344318685656228760863793509418168865967108430523971884258595890393501349300723 [/code] |
A [URL="http://www.factordb.com/index.php?id=1100000000636053336"]P58[/URL] I've found by ECM last week (which broke my previous personal record):
[CODE] GMP-ECM 6.4.4 [configured with MPIR 2.6.0] [ECM] Input number is (3*10^204+7)/(2111*12379*80141*360193*36529453*83762087274812203759) (160 digits) Using B1=260000000, B2=3178559884516, polynomial Dickson(30), sigma=2078429522 Step 1 took 1093707ms Step 2 took 363420ms ********** Factor found in step 2: [URL="http://www.factordb.com/index.php?id=1100000000636053336"]4269986142493572515510539041322472993083083125849142037361[/URL] Found probable prime factor of 58 digits: 4269986142493572515510539041322472993083083125849142037361 Probable prime cofactor ((3*10^204+7)/(2111*12379*80141*360193*36529453*83762087274812203759))/4269986142493572515510539041322472993083083125849142037361 has 102 digits [/CODE]Details [URL="http://homepage2.nifty.com/m_kamada/math/c/30007.htm#N204_C160"]here[/URL]. A [URL="http://www.factordb.com/index.php?id=1100000000636107512"]P53[/URL] found by ECM in step 1 (details [URL="http://homepage2.nifty.com/m_kamada/math/c/28887.htm#N238_C206"]here[/URL]): [CODE] GMP-ECM 6.4.4 [configured with MPIR 2.6.0] [ECM] Input number is (26*10^238-17)/(9*3*31*17914895525348997871953180891109) (206 digits) Using B1=110000000, B2=776278396540, polynomial Dickson(30), sigma=4255384633 Step 1 took 648620ms ********** Factor found in step 1: [URL="http://www.factordb.com/index.php?id=1100000000636107512"]77799771931273889262077139536983524215512156277756839[/URL] Found probable prime factor of 53 digits: 77799771931273889262077139536983524215512156277756839 Probable prime cofactor ((26*10^238-17)/(9*3*31*17914895525348997871953180891109))/77799771931273889262077139536983524215512156277756839 has 153 digits [/CODE] |
[CODE]Msieve v. 1.52 (SVN 886M)
Mon Nov 11 01:03:57 2013 random seeds: 187198dc e395e0be factoring 9999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999992999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999 (253 digits) ...initial square root is modulo 4585129 sqrtTime: 7150 p117 factor: 211857628677636264166676902114066256198845941934180788645905936104472665184004014226679863567582409810768749673482061 p137 factor: 47201510100993602326827859852217555163129145401663287219390072454758015933440888931227171966024510895342063068118093723212737563878094459 [/CODE] |
[CODE]GMP-ECM 6.4.4 [configured with MPIR 2.6.0] [ECM]
Input number is (10^248+3)/(19*223*126165718229274337) (228 digits) Using B1=3000000, B2=5706890290, polynomial Dickson(6), sigma=3741404180 Step 1 took 20467ms Step 2 took 9969ms ********** Factor found in step 2: 16031381961952347637116191005607843989279 Found probable prime factor of 41 digits: 16031381961952347637116191005607843989279 Composite cofactor ((10^248+3)/(19*223*126165718229274337))/16031381961952347637116191005607843989279 has 188 digits [/CODE]Group order: [URL="http://www.factordb.com/index.php?id=2"][COLOR=#000000]2^3[/COLOR][/URL] · [URL="http://www.factordb.com/index.php?id=3"][COLOR=#000000]3^2[/COLOR][/URL] · [URL="http://www.factordb.com/index.php?id=5"][COLOR=#000000]5[/COLOR][/URL] · [URL="http://www.factordb.com/index.php?id=7"][COLOR=#000000]7[/COLOR][/URL] · [URL="http://www.factordb.com/index.php?id=19"][COLOR=#000000]19^3[/COLOR][/URL] · [URL="http://www.factordb.com/index.php?id=163"][COLOR=#000000]163[/COLOR][/URL] · [URL="http://www.factordb.com/index.php?id=1307"][COLOR=#000000]1307[/COLOR][/URL] · [URL="http://www.factordb.com/index.php?id=1487"][COLOR=#000000]1487[/COLOR][/URL] · [URL="http://www.factordb.com/index.php?id=120163"][COLOR=#000000]120163[/COLOR][/URL] · [URL="http://www.factordb.com/index.php?id=134639"][COLOR=#000000]134639[/COLOR][/URL] · [URL="http://www.factordb.com/index.php?id=2337983"][COLOR=#000000]2337983[/COLOR][/URL] · [URL="http://www.factordb.com/index.php?id=77402051"][COLOR=#000000]77402051[/COLOR][/URL] [CODE]GMP-ECM 6.4.4 [configured with MPIR 2.6.0] [ECM] Input number is (10^248+3)/(19*223*126165718229274337*16031381961952347637116191005607843989279) (188 digits) Using B1=3000000, B2=5706890290, polynomial Dickson(6), sigma=1601899263 Step 1 took 14883ms Step 2 took 8283ms ********** Factor found in step 2: 12824921391934305400334065366552991673187 Found probable prime factor of 41 digits: 12824921391934305400334065366552991673187 Probable prime cofactor ((10^248+3)/(19*223*126165718229274337*16031381961952347637116191005607843989279))/12824921391934305400334065366552991673187 has 147 digits [/CODE]Group order: [URL="http://www.factordb.com/index.php?id=2"][COLOR=#000000]2^10[/COLOR][/URL] · [URL="http://www.factordb.com/index.php?id=3"][COLOR=#000000]3^2[/COLOR][/URL] · [URL="http://www.factordb.com/index.php?id=7"][COLOR=#000000]7[/COLOR][/URL] · [URL="http://www.factordb.com/index.php?id=13"][COLOR=#000000]13[/COLOR][/URL] · [URL="http://www.factordb.com/index.php?id=521"][COLOR=#000000]521[/COLOR][/URL] · [URL="http://www.factordb.com/index.php?id=757"][COLOR=#000000]757[/COLOR][/URL] · [URL="http://www.factordb.com/index.php?id=5209"][COLOR=#000000]5209[/COLOR][/URL] · [URL="http://www.factordb.com/index.php?id=9883"][COLOR=#000000]9883[/COLOR][/URL] · [URL="http://www.factordb.com/index.php?id=74699"][COLOR=#000000]74699[/COLOR][/URL] · [URL="http://www.factordb.com/index.php?id=2923747"][COLOR=#000000]2923747[/COLOR][/URL] · [URL="http://www.factordb.com/index.php?id=3448573771"][COLOR=#000000]3448573771[/COLOR][/URL] |
[QUOTE=Batalov;358988][CODE]Msieve v. 1.52 (SVN 886M)
Mon Nov 11 01:03:57 2013 random seeds: 187198dc e395e0be factoring 9999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999992999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999 (253 digits) ...initial square root is modulo 4585129 sqrtTime: 7150 p117 factor: 211857628677636264166676902114066256198845941934180788645905936104472665184004014226679863567582409810768749673482061 p137 factor: 47201510100993602326827859852217555163129145401663287219390072454758015933440888931227171966024510895342063068118093723212737563878094459 [/CODE][/QUOTE] Impressive. How long did it take? How much processing power? |
It was about 25 thousand hours for sieving, two hrs for filtering, 24 hours LA (on an 4x8 MPI grid), and two hours per sqrt.
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Further exploration of pointless places
I ran 480 curves at 1e7 on {60..79}^512+1 over Christmas
No complete factorisations; a couple of new factors of interest: [code] e62:Found probable prime factor of 30 digits: 415279119367083281900859703297 e77:Found probable prime factor of 33 digits: 341126180420063151380968669975553 e65:Found probable prime factor of 37 digits: 1869269849997935174077690896845848577 e75:Found probable prime factor of 38 digits: 13734192372070026415774074593138282497 e65:Found probable prime factor of 43 digits: 4769997756860644904012186212092431977208833 [/code] This was clearly untouched ground, I found a ten-digit factor of 79^512+1 that wasn't in factordb. |
Reverse Smarandache numbers
Hi,
the last days I've factored 2 Reverse Smarandache type numbers for n=103 and n=104. [URL=http://factordb.com/index.php?id=1100000000135133658]RSm(103)[/url].C160 = P53 * P108 Running yafu over night: prp53 = 22633393225636817509048253413614523936779379142819839 (curve 50 stg2 B1=260000000 sigma=4172026601 thread=1) Finished 400 curves using Lenstra ECM method on C160 input, B1=260M, B2=gmp-ecm Default [URL=http://factordb.com/index.php?id=1100000000135133983]RSm(104)[/url].C149 = P52 * P97 Running msieve: total time: 85.26 hours. Intel64 Family 6 Model 58 Stepping 9, GenuineIntel processors: 8, speed: 3.39GHz Windows-7-6.1.7601-SP1 Running Python 2.7 Both reported to [URL=http://users.skynet.be/worldofnumbers/]World of numbers[/url]. Also shown on [URL=http://www.rieselprime.de/Others/Smarandache.htm]my page[/url]. |
[URL=http://factordb.com/index.php?id=1100000000135134178]Reverse Smarandache for n=105, C156[/url] factored in:
r1=505609049620430043564818948424594740095377638674786008583783558052966689 (pp72) r2=1460218912197798897796479876892816487811802580775089126778648005904642208642833062339 (pp85) |
rSm(106) C167 is factored
[CODE]GMP-ECM 6.2.3 [powered by GMP 4.3.1] [ECM] Input number is 18177692096553830368675737725463580456289708131712261558393850692666532966863437168425047460718124572874681287411912149791448198810931545176347119222043777538034560927 (167 digits) Using B1=110000000, B2=776278396540, polynomial Dickson(30), sigma=2318285213 Step 1 took 434355ms Step 2 took 41233ms ********** Factor found in step 2: 414338872062791501547344020582712133249557 Found probable prime factor of 42 digits: 414338872062791501547344020582712133249557 Probable prime cofactor 43871558577296772025736976053227175068325706197701002055248304277569975777948248915189631633909304741312836729962564905149411 has 125 digits[/CODE] |
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