- Hi All,

234043271+N*481789017*7001#+1 (0 < N < 6) describes a 3019 digit ap7 of primes

Haven't finished processing the 4543646 prps (N=1,000,000,000-3,000,000,000)

extending all ap4s up (and most down - I should have started at N>1,000,000,000) yet so don't have final stats.

Got a bit lucky as I had only found 83 ap6s when the ap7 popped up.

I have already listed the 52 ap6s that have term 6 < 2,600,000,000

cheers

Ken

p.s. While hunting I also found the following ap4 which I found interesting

2834722253+N*7001#+1 (0 < N < 3)

which describes a 3019 digit ap4 of primes with difference 7001#

Primality testing 234043271*7001#+1 [N-1, Brillhart-Lehmer-Selfridge]

Running N-1 test using base 2

Running N-1 test using base 3

Calling Brillhart-Lehmer-Selfridge with factored part 33.40%

234043271*7001#+1 is prime! (3.4101s+0.0025s)

Primality testing 715832288*7001#+1 [N-1, Brillhart-Lehmer-Selfridge]

Running N-1 test using base 7057

Calling Brillhart-Lehmer-Selfridge with factored part 33.37%

715832288*7001#+1 is prime! (3.1254s+0.0020s)

Primality testing 1197621305*7001#+1 [N-1, Brillhart-Lehmer-Selfridge]

Running N-1 test using base 7

Calling Brillhart-Lehmer-Selfridge with factored part 33.46%

1197621305*7001#+1 is prime! (3.0342s+0.0020s)

Primality testing 1679410322*7001#+1 [N-1, Brillhart-Lehmer-Selfridge]

Running N-1 test using base 2

Calling Brillhart-Lehmer-Selfridge with factored part 33.42%

1679410322*7001#+1 is prime! (3.0399s+0.0019s)

Primality testing 2161199339*7001#+1 [N-1, Brillhart-Lehmer-Selfridge]

Running N-1 test using base 11

Calling Brillhart-Lehmer-Selfridge with factored part 33.37%

2161199339*7001#+1 is prime! (3.0163s+0.0020s)

Primality testing 2642988356*7001#+1 [N-1, Brillhart-Lehmer-Selfridge]

Running N-1 test using base 7019

Calling Brillhart-Lehmer-Selfridge with factored part 33.34%

2642988356*7001#+1 is prime! (3.1304s+0.0020s)

Primality testing 3124777373*7001#+1 [N-1, Brillhart-Lehmer-Selfridge]

Running N-1 test using base 19

Calling Brillhart-Lehmer-Selfridge with factored part 33.38%

3124777373*7001#+1 is prime! (3.0224s+0.0020s) - ---- djbroadhurst <d.broadhurst@...> wrote:
>

I don't know how easy it would be to use the cudaFFT library to do a PRP test. I was thinking that sieving should be able to go much deeper, thus reducing the number of PRP tests one needs to do to discover a new AP.

>

> --- In primeform@yahoogroups.com,

> "kraDen" <kradenken@...> wrote:

>

> > > With a GPU based app, I wonder how much faster one

> > > could discover record APs?

> > Don't think I haven't been trying.

> > I haven't managed to get CUDA to work on my machine yet

> > (Though I do have a card that supports it)

>

> Mark's original question was apposite.

>

> At large FFT sizes, I was amazed by a statistic, on

> http://primes.utm.edu/primes/page.php?id=104592

>

> Just look at this:

> http://www.primegrid.com/forum_thread.php?id=4068

> > The prime is 1,528,413 digits long...

> > This GPU took about 1 hour 30 minutes to probable prime

> > (PRP) test with GenefCUDA.

--Mark