[QUOTE=VBCurtis;431726]I don't post my riesel factorizations to factordb, just to Mr Klasson's site mklasson.com/factors.[/QUOTE]

Would any of them be smaller that 120 digits? I've factored quite a few numbers of form k.2^n-1 from factordb up to 119 digits and would not like to duplicate work already done.

Chris

Mr Klasson's site tracks only k up to 15, and all our remaining composites are 140 digits or larger. I've done a tiny bit of work on k = 17, but just a few CPU-days; I haven't reported those anywhere 'cause I didn't get very far.

c148 from aliquot sequence 408744:3148
[CODE]
# norm 3.422363e-14 alpha -5.936394 e 8.106e-12 rroots 3
n: 1939235571660442813608521123434086136566665985795776526640156438531510063789721209109117030743430409872362039274329991351238526535353904463675807293
skew: 2404280.47
c0: 233883264091628136257904310643233100
c1: 556563406433388443697653664984
c2: 35679083825503403846141
c3: -292727754019326750
c4: 52297325102
c5: 9384
Y0: -46030775765190921922799593593
Y1: 20896840736748613
[/CODE]

Info for a smaller composite:

c142 from aliquot 230916:4353

nfs: best poly = # norm 1.452046e-013 alpha -7.449783 e 1.839e-011 rroots 5

[CODE]n: 2214530379364092803459638419536438964802657787609806173924788906066752569852980243396068528822409949982646950184731021275523496063306697681557
skew: 4298464.62
c0: -133976463209871790707384401241967320
c1: 187123613165673476928418960866
c2: 582640885581702975557647
c3: -118486544502128332
c4: -29754859796
c5: 336
Y0: -5804839216569921148884028637
Y1: 1299585929038877
rlim: 16000000
alim: 16000000
lpbr: 28
lpba: 28
mfbr: 56
mfba: 56
rlambda: 2.6
alambda: 2.6[/CODE]

A C155 from 119!-5:

[CODE]
n:14983833053669267073388859640749386761592128691535474632716887403740027331275486495085918514582693799340373342068801035123016311177538173489337402480577483
skew 5708636.19, size 5.616e-015, alpha -7.542, combined = 3.121e-012 rroots = 5
R0: -850553565122869061034261830287
R1: 18849943498486567
A0: 172196109872180577784598294873273361360
A1: 51833966860496483626341772381252
A2: -41070998680490039762041384
A3: -6784822293841150427
A4: 1635166252008
A5: 33660
[/CODE]

c151 from aliquot sequence 342144:443
[CODE]
n: 1057572529953947070986938242548533726767656546881332202207999800177097248084986188497807677378705213106913529877330809960101368031087345156307598824387
skew 9780541.55, size 1.494e-14, alpha -7.045, combined = 5.583e-12 rroots = 5
R0: -192547063000931257915545809262
R1: 4436889611965919
A0: 48278227434498164276953134432192997525
A1: 43535400704061552233504534289680
A2: -6992291974079133447242434
A3: -1132852896075083372
A4: 75631249005
A5: 3996
[/CODE]

C146
 

cofactor of (136*10^208-1)/9
[url]http://stdkmd.com/nrr/c.cgi?q=15111_208[/url]
[code]
# Murphy_E = 1.23248345e-11, selected by Maksym Voznyy
# selected by CADO-NFS
n: 11133083975614393174618106789842541849999798450075953644503853715832934826650529799267849607478318984750751468487348433361620156657048935628137667
Y0: -8465139152662472823271804899
Y1: 217586749880489433607
c0: 40603904011815270118467328499250
c1: -7258916478497188892538718405
c2: 26792661013772231492628
c3: 394898230885063231
c4: 69401799606
c5: 1534680
skew: 196661.06596
type: gnfs
[/code]

C142
 

cofactor of (10^216+71)/9
[url]http://stdkmd.com/nrr/cont/1/11119.htm#N216_C142[/url]
[code]
# Murphy_E = 2.01586429e-11, selected by Maksym Voznyy
# selected by CADO-NFS
n: 3588400670974042702680837405464660540266389269005727836794465390573635642433026540041089934357245315252071761211898253220884617929306428555561
Y0: -3951518283918039803675904937
Y1: 4944813883904086457
c0: 4154836225756427964694338997956720
c1: 84338193174923556177344446154
c2: -14212371709515276223669
c3: -56200227425000130
c4: 3755305958
c5: 3720
skew: 2057884.15124
type: gnfs
[/code]

C157
 

cofactor of (58*10^224+23)/9
[url]http://stdkmd.com/nrr/c.cgi?q=64447_224[/url]
[code]
# Murphy_E = 2.74132554e-12, selected by Maksym Voznyy
# selected by cado-nfs-2.2.0
n: 3052808714827299474913563042768663387446103747677187192092256054878499303741346332759423101801264392420724180666344408744793985066320550196201898450311255111
Y0: -2918999876811939818911761664529
Y1: 65491369105410737643217
c0: 1027302415368579954614447177408865340
c1: 5357797564515979755713712585209
c2: 7717777084391720884069418
c3: -3919335731067285077
c4: -874303257420
c5: 280800
skew: 2366600.14884
type: gnfs
[/code]

C172
 

cofactor of 13*2^905-1
poly found by CADO-NFS
[url]http://ftp.mersenneforum.org/showpost.php?p=449463&postcount=759[/url]
[code]
Msieve v. 1.52 (SVN 958)
N=1374250293977900524006825181025041222391785962418349198188752592542556833408706796147779390990626204883096007787340300959668458776589915992783964729160514357520386806570509
R0: -2428783629542938000277341534964669
R1: 66381298897887862049
A0: 1684917805428384144779731520398675160500
A1: -3745304290230496073233576119438452
A2: -2342124466784250014333947213
A3: 259669333218732646325
A4: 9553108753746
A5: 97560
skew 13056627.55, size 1.255e-016, alpha -7.189, combined = 3.338e-013
[/code]

C156
 

[QUOTE=richs;431677]C156 from Aliquot sequence 829332:3605. Poly found by VBCurtis.

[CODE]N 163727926668678035939618053446364480300300719840063508810834694701350128493871168693101567743639977109458829559656666787504985092716814050668990858237669441
SKEW 2799412.69
R0 -1146089445280446698217724846984
R1 29984411104464641
A0 -8388623445446886233513062917901701375
A1 8123777995019347585820981509456
A2 5398445052487820593051471
A3 -3891197957664010388
A4 -1016172369612
A5 82800
#skew 2799412.69, size 4.507e-15, alpha -6.202, combined = 2.765e-12 rroots = 5[/CODE][/QUOTE]

Optimized by CADO-NFS:
[code]
Y0: -1146089485327806075807326154430
Y1: 29984411104464641
c0: -2790893747295827131295746006836959259
c1: -2365843220115152814791290474280
c2: 8140892661148809990618571
c3: 3014648022519417100
c4: -1569113253612
c5: 82800
skew: 2591483.69774
# lognorm 48.45, E 42.01, alpha -6.44 (proj -2.68), 5 real roots
# MurphyE(Bf=1.00e+07,Bg=5.00e+06,area=1.00e+16)=2.89031034e-12
[/code]