POST LOTS AND LOTS AND LOTS OF PRIMES HERE - Page 17

lsoule · 2006-02-08, 18:42

I sieved up to 700bn and only had 840 candidates per 100k. Along with
that low # of candidates per thousand is a low # of primes. The risk
of a really low-weight k like this is that you won't find *any* primes.
To find the low-weight k's for k<300, I sieved n=0-10k up to 100M.
Below is the number of candidates left, # of primes in n=0-5k, and K

Code:

Weight   Primes     K
186	7	283
185	6	269
178	7	101
176	4	29
169	6	221
146	4	251
145	8	223
130	2	239
117	3	191
116	3	127
107	5	247
53	3	253

For comparison, K=25 had 582 candidates left and 21 primes. The highest
weight was K=195 with 1466 candidates and 37 primes.

amphoria · 2006-02-08, 20:06

From test your own k:

5169615*2^294163-1 (88559 digits)

lsoule · 2006-02-09, 04:00

From choose your own k - the 5th reported prime for this k
22932195*2^313832-1 (94481 digits)

Kosmaj · 2006-02-10, 01:22

My first megabit prime

77*2^1467554-1 (441780 digits)

After realizing that k=77 is a promising multiplier, and finding the primes at 607k (in December 2004) and 855k (in June last year) I decided to test megabit candidates working from 1M forward and from 1.5M backward. It was a time consuming "operation" but it payed off!

grobie · 2006-02-10, 02:27

WTG, very nice

Cruelty · 2006-02-10, 06:43

Great prime Kosmaj!

Kosmaj · 2006-02-10, 13:40

Grobie and Cruelty, thanks!

Here is one more big one

2995125705*2^891645-1 (268422 digits)

This one eluded us for quite a while! And it closely matches Larry's forecast (890k) based on previous largest gap.

lsoule · 2006-02-10, 14:39

Great primes Kosmaj!

This is the new largest gap. Duplicating the largest gap would have put this prime at n=891578!

lsoule · 2006-02-10, 14:43

BTW, this puts our project score ahead of 15k already. Now #3 in primes
and #10 in score.

lsoule · 2006-02-10, 16:02

80555475*2^281095-1 (84626 digits)

grobie · 2006-02-12, 01:23

1222853775*2^249279-1 (75050 digits)

2006-02-08, 18:42	#177
lsoule Nov 2004 California 2³×3×71 Posts	I sieved up to 700bn and only had 840 candidates per 100k. Along with that low # of candidates per thousand is a low # of primes. The risk of a really low-weight k like this is that you won't find any primes. To find the low-weight k's for k<300, I sieved n=0-10k up to 100M. Below is the number of candidates left, # of primes in n=0-5k, and K Code: Weight Primes K 186 7 283 185 6 269 178 7 101 176 4 29 169 6 221 146 4 251 145 8 223 130 2 239 117 3 191 116 3 127 107 5 247 53 3 253 For comparison, K=25 had 582 candidates left and 21 primes. The highest weight was K=195 with 1466 candidates and 37 primes.

2006-02-10, 01:22	#180
Kosmaj Nov 2003 2·1,811 Posts	Megabit My first megabit prime *772^1467554-1** (441780 digits) After realizing that k=77 is a promising multiplier, and finding the primes at 607k (in December 2004) and 855k (in June last year) I decided to test megabit candidates working from 1M forward and from 1.5M backward. It was a time consuming "operation" but it payed off!

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2006-02-08, 20:06	#178
amphoria "Dave" Sep 2005 UK 5330₈ Posts	From test your own k: 5169615*2^294163-1 (88559 digits)

2006-02-09, 04:00	#179
lsoule Nov 2004 California 11010101000₂ Posts	From choose your own k - the 5th reported prime for this k 22932195*2^313832-1 (94481 digits)

2006-02-10, 02:27	#181
grobie Sep 2005 Raleigh, North Carolina 337₁₀ Posts	WTG, very nice

2006-02-10, 06:43	#182
Cruelty May 2005 2³·7·29 Posts	Great prime Kosmaj!

2006-02-10, 13:40	#183
Kosmaj Nov 2003 2·1,811 Posts	Grobie and Cruelty, thanks! Here is one more big one *29951257052^891645-1** (268422 digits) This one eluded us for quite a while! And it closely matches Larry's forecast (890k) based on previous largest gap.

2006-02-10, 14:39	#184
lsoule Nov 2004 California 1704₁₀ Posts	Great primes Kosmaj! This is the new largest gap. Duplicating the largest gap would have put this prime at n=891578!

2006-02-10, 14:43	#185
lsoule Nov 2004 California 2³·3·71 Posts	BTW, this puts our project score ahead of 15k already. Now #3 in primes and #10 in score.

2006-02-10, 16:02	#186
lsoule Nov 2004 California 2³·3·71 Posts	80555475*2^281095-1 (84626 digits)

2006-02-12, 01:23	#187
grobie Sep 2005 Raleigh, North Carolina 151₁₆ Posts	1222853775*2^249279-1 (75050 digits)