20220622, 11:05  #529 
May 2009
Moscow, Russia
5515_{8} Posts 
Rather rare ECM hit  P50 with B1=1e6 on aliquot sequence 213720:i1748
Code:
06/22/22 10:47:52, scheduled 781 curves at B1=1000000 toward target pretesting depth of 34.77 06/22/22 10:56:22, prp50 = 10393259545295633660028312292669510525032755549983 (curve 576 stg2 B1=1000000 sigma=2114364744 thread=3) 06/22/22 10:56:23, Finished 578 curves using GMPECM method on C113 input, B1=1M, B2=gmpecm default 
20220804, 19:20  #530 
(loop (#_fork))
Feb 2006
Cambridge, England
2·7·461 Posts 
G204 from L1432
Code:
Sat Jun 18 11:14:36 2022 commencing relation filtering Sat Jun 18 11:14:36 2022 setting target matrix density to 130.0 Sat Jun 18 16:39:32 2022 found 253785883 hash collisions in 884618379 relations Sat Jun 18 16:56:21 2022 found 249640336 duplicates and 634978043 unique relations Sat Jun 18 21:50:05 2022 keeping 642646661 ideals with weight <= 200, target excess is 3337339 Sun Jun 19 03:10:29 2022 weight of 61398287 cycles is about 7982480398 (130.01/cycle) Mon Jun 20 16:55:50 2022 matrix is 61396802 x 61397217 (28544.7 MB) with weight 6879882710 (112.06/col) Mon Jun 20 16:55:50 2022 sparse part has weight 6500470301 (105.88/col) Mon Jun 20 16:55:50 2022 using block size 8192 and superblock size 473088 for processor cache size 19712 kB Mon Jun 20 16:58:58 2022 commencing Lanczos iteration (14 threads) Mon Jun 20 16:58:58 2022 memory use: 39165.2 MB Mon Jun 20 17:00:52 2022 linear algebra at 0.0%, ETA 1056h51m Mon Jun 20 17:01:25 2022 checkpointing every 60000 dimensions Thu Aug 4 01:20:22 2022 lanczos halted after 240551 iterations (dim = 61396800) Thu Aug 4 01:24:54 2022 recovered 29 nontrivial dependencies Thu Aug 4 01:25:11 2022 BLanczosTime: 3838234 Thu Aug 4 01:25:11 2022 elapsed time 1066:10:34 Thu Aug 4 09:03:42 2022 Thu Aug 4 09:03:42 2022 Thu Aug 4 09:03:42 2022 Msieve v. 1.54 (SVN 1030M) Thu Aug 4 09:03:42 2022 random seeds: 13b713d5 bb171d5a Thu Aug 4 09:03:42 2022 factoring 235690490213264657463900217730943824554528801527148146000741132394289637021389555084534044618776128084370642121517338234516897475536672909156227425053218472454497341488127093035620464801567308818878368161 (204 digits) Thu Aug 4 09:03:42 2022 no P1/P+1/ECM available, skipping Thu Aug 4 09:03:42 2022 commencing number field sieve (204digit input) Thu Aug 4 09:03:42 2022 R0: 2530528376362098551295006697188264488331 Thu Aug 4 09:03:42 2022 R1: 869607471902015319334451 Thu Aug 4 09:03:42 2022 A0: 4794286155561978100243308360517944857334122844056 Thu Aug 4 09:03:42 2022 A1: 225816378627344837726832138347030302060794 Thu Aug 4 09:03:42 2022 A2: 93310870436284966139238827232264 Thu Aug 4 09:03:42 2022 A3: 8511608197480840558280241 Thu Aug 4 09:03:42 2022 A4: 425430523159498 Thu Aug 4 09:03:42 2022 A5: 2271360 Thu Aug 4 09:03:42 2022 skew 295921789.67, size 5.084e20, alpha 7.573, combined = 2.642e15 rroots = 5 Thu Aug 4 09:03:42 2022 Thu Aug 4 09:03:42 2022 commencing square root phase Thu Aug 4 09:03:42 2022 reading relations for dependency 1 Thu Aug 4 09:03:47 2022 read 30710593 cycles Thu Aug 4 09:04:54 2022 cycles contain 112671476 unique relations Thu Aug 4 09:12:29 2022 read 112671476 relations Thu Aug 4 09:22:12 2022 multiplying 112671476 relations Thu Aug 4 11:41:27 2022 multiply complete, coefficients have about 7305.03 million bits Thu Aug 4 11:42:01 2022 initial square root is modulo 155615419 Thu Aug 4 14:14:51 2022 sqrtTime: 18669 Thu Aug 4 14:14:51 2022 p78 factor: 305243370577692687562023127362819254670248796601352698266538583812016117141423 Thu Aug 4 14:14:51 2022 p126 factor: 772139587396133334683063918926732402964306604392061079545291898181089775086186502933346070065885090044744147103538539121983407 And that will be my last GNFS for at least six months: electricity prices went up 50% on 1 August and will probably do the same on 1 October, and it's not clear they won't repeat the feat on 1 February unless Russia has withdrawn from Ukraine. I've got one quite large machine finishing the linear algebra for a chunky GNFS, then that will be turned off too. 
20220904, 17:27  #531 
Apr 2020
3A1_{16} Posts 
Here's an appropriate factorization for this year, the remaining c254 from Lucas(2022):
Code:
GMPECM 7.0.4 [configured with GMP 6.2.0, enableasmredc] [ECM] Input number is 17043226212783711742692308352443276499400658098753327819501534654672554845581878196705469653377915256927593169134716672601053118012377752867908416100610501619508291840715333650019524556526012952526433385912016538133828203922048908102059105444697554676627 (254 digits) Using B1=260000000, B2=3178559884516, polynomial Dickson(30), sigma=1:2462713740 Step 1 took 733672ms Step 2 took 12674ms ********** Factor found in step 2: 888285660164970474822081669480069094779067491081831700922212921 Found prime factor of 63 digits: 888285660164970474822081669480069094779067491081831700922212921 Prime cofactor 19186650170192414176618016901095139662376929725775303789682249289092445419018547802891487877574732798741719639308992829186693199949338239528309686740732630002027857441437496294313013167852587 has 191 digits 
20220916, 00:20  #532 
May 2009
Moscow, Russia
11×263 Posts 
Factor for the nearrepdigit (4×10^2819×10^1404)/9 C249 cofactor.
Never saw such a big factor to be found in stage 1 (B1=11e6). Code:
GPU: factor 52041130226646410775815807841622362433337587803053 found in Step 1 with curve 105 (sigma 3:528261764) Computing 1792 Step 1 took 1075ms of CPU time / 981668ms of GPU time Throughput: 1.825 curves per second (on average 547.81ms per Step 1) ********** Factor found in step 1: 52041130226646410775815807841622362433337587803053 Found prime factor of 50 digits: 52041130226646410775815807841622362433337587803053 Prime cofactor 3115122236209527245863488220654856326097488696703450437349569644219317336991254462329618151832113903741198458885747233029658280515683477665124585955217173657120994666331305559853031029378940683694619 has 199 digits 
20230203, 15:39  #533 
May 2009
Moscow, Russia
11×263 Posts 
P63 from aliquot sequence 11040 index 10239. Top3 of the year, I've sent it to Paul Zimmerman.
I've found a P56 at index 10233 after doing like ~30k of 26e7 curves and now I'm awarded by this P63 after only 9k@11e7 curves done. The probabilistic nature of ECM, you know Code:
Resuming ECM residue saved by @3985e1efbbef with GMPECM 7.0.5dev on Thu Feb 2 02:53:54 2023 Input number is 237904517022802820757224368587364782006325905330885694395095252119996369998385411124752456284896341672211547713762103559363264566580436437145644261215852903299061333939322009157966102169289310723 (195 digits) Using B1=110000000110000000, B2=776278396540, polynomial Dickson(30), sigma=3:118986867 Step 1 took 0ms Step 2 took 111478ms ********** Factor found in step 2: 899623267406694477612383357166705728333731850906858901316130399 Found prime factor of 63 digits: 899623267406694477612383357166705728333731850906858901316130399 Prime cofactor 264449048442910995926523564064809276353761382491328280534807657592256491907743902028720830344914019940556283479864008593664844730077 has 132 digits 
20230204, 08:55  #534 
"Seth"
Apr 2019
479_{10} Posts 
Congratulations on the factor! Requires at least B1=70e6, B2=61e9

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