[QUOTE=kar_bon;267374]Sure, misleading used phrase of mine. Thanks for the remark.[/QUOTE]

And what is the difference between the 258 and 257?

I'd like to reserve [B]k=2889081195[/B] which has a very high Nash weight (7000+) but it has not been worked on for ages and seems to be available.

If so, I'll start sieving on it when I get the approval.

We can't really give any sort of formal approval. However, this k has clearly not been worked on for a long time so go ahead and reserve it.

[QUOTE=amphoria;267587]We can't really give any sort of formal approval. However, this k has clearly not been worked on for a long time so go ahead and reserve it.[/QUOTE]

OK. Well I will start sieving on it later tonight when I have a core freed up, no harm in doing that at least. I ordered a new computer which should be delivered one day next week. By then this k will be sieved pretty good and I'll give it to my new computer if there has been no further objections by then.

[QUOTE=SaneMur;267578]And what is the difference between the 258 and 257?
[/QUOTE]

See the file 'newpgenformats.txt' given with NewPGen.exe:

[code]
// Here are the NewPGen format's
<sieve limit>:<mode character>:<chain len>:<base>:<mode bitmap as a decimal>

Mode character:
'P' +1
'M' -1
(...)

BitMap:
0x0001 k*2^n+1 k*n#+1
0x0002 k*2^n-1 k*n#-1
0x0004 k*b^(n+1)+1 2k*n#+1
0x0008 k*b^(n+1)-1 2k*n#-1
0x0010 k*b^(n-1)+1 .5k*n#+1
0x0020 k*b^(n-1)-1 .5k*n#-1
0x0040 Primorial
0x0080 3-tuple and 4-tuple (PLUS5 - used in the triplet sieve.)
0x0100 Mode 'k' sieve (variable k's)
[/code]

So 258 (dez) is 102 (hex) (combination of 0x0100 and 0x0002) -> "Mode 'k' sieve (variable k's)" for "k*2^n-1" and
257 (dez) is 101 (hex) -> "Mode 'k' sieve (variable k's)" for "k*2^n+1".

My new computer arrived this morning, ahead of schedule, what a nice surprise.

An even better surprise: In less than 6 hours of use, it has found a top 5000 prime!

I am happy to report my first top-5000 prime should come in around #2209:

[B](11235813 * (2^775082)) - 1[/B] is prime!

SaneMur-
Congratulations! Way to break in your new machine. A little beginner's luck mixed with a lot of enthusiasm- it's fun to see someone find their first.

Note we have a thread specifically dedicated to reporting primes- now that you're finding top-5000 primes, you should use that thread too. The threads are helpfully named; this current thread for reservations and occasional status updates, the prime reporting thread for just that.
-Curtis

[QUOTE=VBCurtis;267978]SaneMur-
Congratulations! Way to break in your new machine. A little beginner's luck mixed with a lot of enthusiasm- it's fun to see someone find their first.
[/QUOTE]

Thanks!

I'd also like to credit my 5.4 gigahertz computer! This thing is loud, heavy, and fun to watch (from the next room).

This thread is called "Choose your own K and work on finding a top-5000 prime!" so did I not post this in the correct place? I surely chose my own K and made it to the top 5000.

Well Hurricane Irene was not too kind to us. No real serious damage from falling trees or anything, but lots and lots of water. Fire company had to come and pump out the basement. One of my two computers is done for (fortunately not the new one).

Just restarted doing some primes so nothing to post in terms of updates.

k=7605
 

k=7605 is now at 1240k and the total of 102 primes have been found.

The first 100 primes, up to 892k, I reported [URL="http://www.mersenneforum.org/showpost.php?p=263539&postcount=369"]here[/URL]

Primes found between 892k and 1240k:
7605*2^1016474-1 (305994 digits)
7605*2^1027719-1 (309379 digits)

would like to reserve k=314159

It has been quite a long time since I updated the k's I work on above 300:
k = 405 complete to 1.41M
k = 443 complete to 2.31M
k = 2115 complete to 1.33M
k = 2145 complete to 1.36M
k = 2175 complete to 1.27M

405 and 443 ran on ancient P4-celerons until recently, so progress was very slow. 405 is now on a new i3 laptop, 443 on i7 desktop.
The 2000's are in cooperation with sjtjung (Steven) and chaos13 (Kristine).