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 2011-12-25, 17:38 #386 SaneMur   Jul 2011 32×13 Posts Riesel primes with k = 25790513410853719562625473025 exist for n = 16, 21, 26, 28, 32, 33, 36, 37, 38, 39, 45, 54, 56, 57, 59, 60, 67, 68, 76, 86, 101, 106, 134, 135, 138, 146, 155, 157, 170, 188, 190, 209, 220, 224, 243, 255, 258, 276, 351, 353, 381, 392, 395, 416, 425, 502, 511, 564, 600, 646, 657, 671, 691, 720, 741, 790, 793, 854, 861, 869, 887, 895, 922, 926, 969, 997, 998, 1037, 1049, 1128, 1294, 1387, 1398, 1478, 1562, 1606, 1663, 1745, 1758, 2208, 2277, 2331, 2386, 2391, 2431, 2535, 2760, 2988, 3053, 3454, 3693, 4047, 4357, 4486, 4689, 5918, 5967, 6539, 6737, 6751, 6823, 6825, 6860, 7427, 7512, 7676, 8203, 8211, 8408, 8713, 10256, 10337, 10976, 11494, 12295, 14691, 14902, 16110, 16845, 17473, 19418, 24014, 25584, 29989, 30672, 31307, 34951, 38689, 38843, 41032, 41763, 45833, 53454, 54576, 62344, 73453, 74468, 75052, 77089, 81964, 83305, 95724, 105116, 112777, 116080, 120073 Searched up to: 125K Reserving this constant for future work
 2011-12-25, 17:40 #387 SaneMur   Jul 2011 32×13 Posts (bold = new prime) Riesel primes with k = 10000000001 exist for n = 2, 50, 326, 482, 902, 1638, 28286, 219506 Searched up to: 250K Last fiddled with by SaneMur on 2011-12-25 at 17:41
 2011-12-27, 17:53 #388 firejuggler     Apr 2010 Over the rainbow 43×59 Posts k= 2712, b =2011 prime n : 0 2 18 36 120 142 4511 searched up to n=5600 (still searching) odd and even exponent prime? Last fiddled with by firejuggler on 2011-12-27 at 17:55
2012-01-01, 23:03   #389
Thomas11

Feb 2003

77416 Posts

Quote:
 Originally Posted by firejuggler k= 2712, b =2011
The primes you reported are for the type k*b^n-1, right? At least the first one, n=0, is a twin prime.

Quote:
 Originally Posted by firejuggler odd and even exponent prime?
Since you have an odd base and an even multiplier (k), there's no (obvious) limitation for the exponent (n). Even and odd exponents both yield odd numbers, which might be primes.
Of course, for some specific (k,b) combinations there may exist some (small) factors which eliminate all odd or all even exponents, thus yielding only even or only odd exponent primes.
For example: p=3 divides 5*2^n-1 for odd exponents and 7*2^n-1 for even exponents.

Note, that for the new year (b=2012) there's no restriction on the multiplier (for b=2011 the k had to be an even number). Thus you can test January, February, March, ...

BTW.: Happy New Year!

Last fiddled with by Thomas11 on 2012-01-01 at 23:04

 2012-01-07, 13:19 #390 sjtjung     Mar 2006 Columbus, OH 7·11 Posts 2055*2^667599-1 is prime. (200971 digits)
 2012-03-11, 23:20 #391 otutusaus   Nov 2010 Ann Arbor, MI 2·47 Posts k=3011-3999 Reserving k=3011-3999 to n=200k (initially). Any work previously done will be DC'ed.
 2012-03-19, 19:00 #392 firejuggler     Apr 2010 Over the rainbow 43·59 Posts k=9884615561, b=2, n=1-1e6 Code: 9884615561*2^7+1 9884615561*2^13+1 9884615561*2^49+1 9884615561*2^105+1 9884615561*2^159+1 9884615561*2^177+1 9884615561*2^219+1 9884615561*2^1057+1 9884615561*2^1255+1 9884615561*2^2935+1 9884615561*2^4137+1 9884615561*2^4263+1 9884615561*2^5877+1 9884615561*2^6123+1 9884615561*2^15479+1 9884615561*2^33603+1 9884615561*2^37845+1 9884615561*2^39525+1 9884615561*2^57669+1 9884615561*2^64239+1 9884615561*2^81337+1 9884615561*2^173523+1 9884615561*2^245097+1 9884615561*2^299229+1 at n=405k atm, will go untill i find a top-5000 (around n=660k?)
2012-03-20, 04:42   #393
Kosmaj

Nov 2003

2·1,811 Posts

Quote:
 Originally Posted by firejuggler at n=405k atm, will go untill i find a top-5000 (around n=660k?)
Well, no, now it's around 728k, and by the time you find a prime it might be at 750k.

2013-08-16, 00:26   #394
c10ck3r

Aug 2010
Kansas

22316 Posts
Small Primes

Well, I don't really see a better place for these at the moment, so...
Until further notice, post small Riesel primes here :P

For the following k's tested from 20k to 50k:
Code:
3401
3403
3405
3407
3409
3411
3413
3415
3417
3419
3421
3423
3425
3427
3429
3431
3433
3435
3437
3439
3441
3443
3445
3447
3449
3451
3453
3455
3457
3459
3461
3463
3465
3467
3469
3471
3473
3475
3477
3479
3481
3483
3485
3487
3489
3491
3493
3495
3497
3499
3501
3503
3505
3507
3509
3511
3513
3515
3517
3519
3521
3523
3525
3527
3529
3531
3533
3535
3537
3539
3541
3543
3545
3547
3549
3551
3553
3555
3557
3559
3561
3563
3565
3567
3569
3571
3573
3575
3577
3579
3581
3583
3585
3587
3589
3591
3593
3595
3597
3599
3601
3603
3605
3607
3609
3611
3613
3615
3617
3619
3621
3623
3625
3627
3629
3631
3633
3635
3637
3639
3641
3643
3645
3647
3649
3651
3653
3655
3657
3659
3661
3663
3665
3667
3669
3671
3673
3675
3677
3679
3681
3683
3685
3687
3689
3691
3693
3695
3697
3699
3701
3703
3705
3707
3709
3711
3713
3715
3717
3719
3721
3723
3725
3727
3729
3731
3733
3735
3737
3739
3741
3743
3745
3747
3749
3751
3753
3755
3757
3759
3761
3763
3765
3767
3769
3771
3773
3775
3777
3779
3781
3783
3785
3787
3789
3791
3793
3795
3797
3799
3801
3803
3805
3807
3809
3811
3813
3815
3817
3819
3821
3823
3825
3827
3829
3831
3833
3835
3837
3839
3841
3843
3845
3847
3849
3851
3853
3855
3857
3859
3861
3863
3865
3867
3869
3871
3873
3875
3877
3879
3881
3883
3885
3887
3889
3891
3893
3895
3897
3899
3901
3903
3905
3907
3909
3911
3913
3915
3917
3919
3921
3923
3925
3927
3929
3931
3933
3935
3937
3939
3941
3943
3945
3947
3949
3951
3953
3955
3957
3959
3961
3963
3965
3967
3969
3971
3973
3975
3977
3979
3981
3983
3985
3987
3989
3991
3993
3995
3997
3999
8113
8115
8117
8119
8121
8123
8125
8131
8133
8135
8137
8139
8141
8147
8149
8151
8153
8155
8157
8161
8163
8165
8167
8169
8171
8177
8179
8181
8183
8185
8187
8189
8191
8193
8195
8197
8199
I found the attached primes.
Attached Files
 PRIMES.txt (11.5 KB, 168 views)

 2013-09-07, 14:39 #395 Trilo     "W. Byerly" Aug 2013 1423*2^2179023-1 103 Posts k= 211463471505 25k- 150k 25615 25970 47056 47808 58838 67355 75022 81990 88670 103437 103870 106186 112669 114288 144453 149450 k= 233806014585 25k- 97k: 26934 30618 30685 31887 32406 32522 33299 40113 46377 47353 48537 49659 50517 53276 54727 55136 82108 87801 k= 54896985 10k- 77k 10167 12188 12247 13703 17202 17398 17890 18914 20080 21643 22553 24523 25096 28109 29607 30977 33661 36793 38657 45297 55212 62379 68150 Last fiddled with by Trilo on 2013-09-07 at 14:40
 2015-02-09, 04:13 #396 sjtjung     Mar 2006 Columbus, OH 7·11 Posts 2175*2^876843-1 is prime

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