15*2^n-1, n>1M Reservation Thread

[Kosmaj]

We are now ready to start testing 15*2^n-1, n>1M. The first segment to 1.1M has been sieved to 11.3T by amphoria, Larry, Templus and me. The average number of candidates per file is 48.9.

Happy hunting!

Found primes
15*2^1084010-1 (326321 digits) by Amphoria on Sep 28, 2006
15*2^1344313-1 (404680 digits) by Amphoria on Jan 5, 2007
15*2^1837873-1 (553257 digits) by mcduck on Dec 16, 2008
15*2^2323205-1 (699356 digits) by Thomas11 on Jul 11, 2011
15*2^3668194-1 (1104238 digits) by Ivica on Oct 15, 2013

Status

     Range            Tested by      Status
1,000,000-3,000,000 - RPS         - Complete (4 primes)
3,000,000-3,010,000 - Pepi37      - Complete
3,010,000-3,130,000 - Kosmaj      - Complete
3,130,000-3,150,000 - Pepi37      - Complete
3,150,000-3,170,000 - Kosmaj      - Complete
3,170,000-3,172,570 - Pepi37      - Complete
3,172,570-3,200,000 - Pepi37      - Complete
3,200,000-3,210,000 - Kosmaj      - Complete
3,210,000-3,220,000 - Pepi37      - Complete
3,220,000-3,300,000 - Pepi37      - Complete
3,300,000-3,320,000 - Pepi37      - Complete
3,320,000-3,400,000 - Pepi37      - Complete
3,400,000-3,500,000 - Pepi37      - Complete
3,500,000-3,600,000 - Pepi37      - Complete
3,600,000-3,650,000 - Pepi37      - Complete
3,650,000-3,800,000 - Ivica       - Complete (Prime: 15*2^3668194-1)
3,800,000-3,803,000 - Pepi37      - Complete
3,803,000-3,860,000 - Ivica       - Complete 
3,860,000-3,900,000 - Thomas11    - Complete
3,900,000-4,080,000 - Batalov     - Complete
4,080,000-4,400,000 - Batalov     - Complete
4,400,000-4,700,000 - Batalov     - Complete
4,700,000-4,800,000 - Thomas11    - Complete
4,800,000-5,000,000 - Thomas11    - Complete
5,000,000-5,200,000 - Thomas11    - Complete
5,200,000-5,500,000 - Thomas11    - Complete
5,500,000-5,800,000 - Thomas11    - Complete
5,800,000-6,000,000 - Thomas11    - Complete
6,000,000-6,134,000 - Thomas11    - Complete

Available files
The attached file contains the 4-5M range, including already tested ones.
Please help yourself by extracting the range you want to test.
Extensively sieved by Psieve.
(36432 candidates).

[Kosmaj]

BTW, k=15 up to n=1M so far produced 50 primes, as follows:

#Digits   #primes
2-1000 ....28
1-10k ......5
10-100k ...12
100-300k ...5

The full list of n's:
1, 2, 4, 5, 10, 14, 17, 31, 41, 73, 80, 82, 116, 125, 145, 157, 172, 202, 224, 266, 289, 293, 463, 1004, 1246, 2066, 2431, 2705, 4622, 5270, 7613, 21727, 21962, 40742, 41054, 60622, 83263, 83669, 91457, 103940, 104177, 108124, 115327, 161453, 172714, 454681, 568780, 656264, 712294, 902474

[lsoule]

Taking 1000-1001!

[robert44444uk]

Good work to the sievers, that's what I say.

Taking 1001-1002

Regards

Robert Smith

[lsoule]

Taking 1002-1003

[Kosmaj]

Taking 1003-1005.

As Larry informed me, on a 2.8GHz P-4 it takes less than 23 hrs to process 50 candidates at n=1M. Therefore, for n>1010k I'll release test files in 2k chunks.

[lsoule]

1000-1001 complete, no primes
Taking 1005-1006

[lsoule]

1002-1003 complete, no primes.
Taking 1006-1007

[Kosmaj]

1003-1004 complete, no primes.

Taking 1007-1008.

[robert44444uk]

Taking 1008 - 1010. 1001-1002 produced no primes

Regards

Robert Smith

[lsoule]

1005-1006 complete, no primes.
Taking 1010-1012