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-   -   Carol / Kynea Coordinated Search - Reservations/Status (https://www.mersenneforum.org/showthread.php?t=21216)

lalera 2016-04-17 17:53

hi,
I do like to reserve base=6
n=1 to 50000
for double checking

lalera 2016-04-17 21:07

hi,
cksieve v1.1.0 gives out a warning - what does it means?
[CODE]
cksieve -P20e10 -i ck.in
cksieve 1.1.0 -- A sieve for Carol (b^n-1)^2-2 and Kynea (b^n+1)^2-2 numbers.
Read 16432 terms for (74^n+/-c)^2-2 from ABC file `ck.in'.
cksieve 1.1.0 started: 3 <= n <= 99999, 60000000000 <= p <= 200000000000
p=77153080019, 141204 p/sec, 150 factors, 12.3% done, 0 sec/factor, ETA 18 Apr 08:19
WARNING: 393216 is not a root (mod 77309411329)

p=81621680057, 141347 p/sec, 190 factors, 15.4% done, 0 sec/factor, ETA 18 Apr 08:19
[/CODE]

rogue 2016-04-18 01:15

[QUOTE=lalera;431815]hi,
cksieve v1.1.0 gives out a warning - what does it means?
[CODE]
cksieve -P20e10 -i ck.in
cksieve 1.1.0 -- A sieve for Carol (b^n-1)^2-2 and Kynea (b^n+1)^2-2 numbers.
Read 16432 terms for (74^n+/-c)^2-2 from ABC file `ck.in'.
cksieve 1.1.0 started: 3 <= n <= 99999, 60000000000 <= p <= 200000000000
p=77153080019, 141204 p/sec, 150 factors, 12.3% done, 0 sec/factor, ETA 18 Apr 08:19
WARNING: 393216 is not a root (mod 77309411329)

p=81621680057, 141347 p/sec, 190 factors, 15.4% done, 0 sec/factor, ETA 18 Apr 08:19
[/CODE][/QUOTE]

There is a piece of code that finds x such at x^2 = 2 (mod p). Sometimes (and I mean rarely) it returns x where x^2 = -2 (mod p). I haven't looked into. Chances are well under 1 in a million that a factor is missed because of this.

axn 2016-04-18 03:03

Incidentally, that output also show another bug. The factor removal rate is always "0 sec/factor".

Batalov 2016-04-18 06:19

...and the ETA seems way off. Or it may be in the wrong timezone (but not UTC, as one could immediately expect).

axn 2016-04-18 06:31

[QUOTE=Batalov;431844]...and the ETA seems way off. Or it may be in the wrong timezone (but not UTC, as one could immediately expect).[/QUOTE]
ETA is fine. It is in local timezone. It is the p/sec that is quirky. I believe it is counting actual p's being processed, rather than the p-range being processed (i.e. if it crunched from p=1e9 to p=2e9, it counts it as pi(2e9)-pi(1e9) p's processed rather than a range of 1e9 processed).

rogue 2016-04-18 17:13

[QUOTE=axn;431832]Incidentally, that output also show another bug. The factor removal rate is always "0 sec/factor".[/QUOTE]

I noticed that too. It shouldn't be too hard to fix.

rogue 2016-04-18 17:17

[QUOTE=axn;431847]ETA is fine. It is in local timezone. It is the p/sec that is quirky. I believe it is counting actual p's being processed, rather than the p-range being processed (i.e. if it crunched from p=1e9 to p=2e9, it counts it as pi(2e9)-pi(1e9) p's processed rather than a range of 1e9 processed).[/QUOTE]

Correct. I treat "p/sec" as the number of primes tested per second not the size of the range sieved per second. If I were to use the latter, I wouldn't call it "p/sec" as that is misleading (IMO). ETA and removal rate should be all that one cares about.

rogue 2016-04-18 23:47

In the first post I updated to fix the factor removal rate.

Batalov 2016-04-20 11:33

[QUOTE=axn;432017]All proven primes, and available in factordb (the larger ones apparently cannot be proven in factordb, even though N+1 is adequately factored).[/QUOTE]
I noticed a kludge to get numbers > 30,000 digits (ostensibly, the default limit) proven:

Step 1. We can submit e.g. (40^40778+1)^2-2 -- as (40^40778+2)*40^40778-1
Step 2. Submit for PRP test. Because it has a ...-1 form, N+1 test is also run (or at least I thin this is how it happens).

Then we can query for [URL="http://factordb.com/index.php?id=1100000000834232306"](40^40778+1)^2-2[/URL] and because this is a shorter form it sticks. And it shows as a P.

axn 2016-04-20 11:47

[QUOTE=Batalov;432024]I noticed a kludge to get numbers > 30,000 digits (ostensibly, the default limit) proven:

Step 1. We can submit e.g. (40^40778+1)^2-2 -- as (40^40778+2)*40^40778-1
Step 2. Submit for PRP test. Because it has a ...-1 form, N+1 test is also run (or at least I thin this is how it happens).

Then we can query for [URL="http://factordb.com/index.php?id=1100000000834232306"](40^40778+1)^2-2[/URL] and because this is a shorter form it sticks. And it shows as a P.[/QUOTE]

:tu: This is good to know. Nothing can be done about the ones already reported, but I will use this trick for any future finds.


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