Post small primes and tell us about your progress here - Page 36

SaneMur · 2011-12-25, 17:38

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

SaneMur · 2011-12-25, 17:40

(bold = new prime)

Riesel primes with k = 10000000001
exist for n =

2, 50, 326, 482, 902, 1638, 28286, 219506

Searched up to: 250K

firejuggler · 2011-12-27, 17:53

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?

Thomas11 · 2012-01-01, 23:03

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!

sjtjung · 2012-01-07, 13:19

2055*2^667599-1 is prime. (200971 digits)

otutusaus · 2012-03-11, 23:20

Reserving k=3011-3999 to n=200k (initially).
Any work previously done will be DC'ed.

firejuggler · 2012-03-19, 19:00

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?)

Kosmaj · 2012-03-20, 04:42

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.

c10ck3r · 2013-08-16, 00:26

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:

I found the attached primes.

Trilo · 2013-09-07, 14:39

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

sjtjung · 2015-02-09, 04:13

2175*2^876843-1 is prime

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

2012-03-11, 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.

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

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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

2012-01-07, 13:19	#390
sjtjung Mar 2006 Columbus, OH 7·11 Posts	2055*2^667599-1 is prime. (200971 digits)

2015-02-09, 04:13	#396
sjtjung Mar 2006 Columbus, OH 7·11 Posts	2175*2^876843-1 is prime