Reportable Twin Found

[Flatlander]

Hi

I have found a top 10 twin, what do I type in the prime submission box?

Chris

[TimSorbet]

Judging by the twins already there, I'd guess:

k*2^n-1 Twin (p)
k*2^n+1 Twin (p+2)

Congrats, hope that works.

[Flatlander]

That worked, thank you.

108615*2^110342+-1 is twin prime!

Comes in at 7th place

[Flatlander]

Since finding this twin, I have spent most of my CPU time searchng for a record twin < n=333,333.

So far I've found lots of Riesels, but no twin.
I'd would be nice to hold the record even if it's only for a short while.

[Flatlander]

Now that finding the world's biggest twin is (realistically) out of my reach, I decided to set myself a different challenge.

Thus:
23321624*3^53005+-1 is twin.

Buzz Aldrin was described by David Letterman as 'The first man named Buzz to walk on the moon.' Well, this is the world's biggest twin not of the form k*2^n+-1.

Found with NewPGen and the go-faster WinPFGW.

(A new proof-code, so there might be a delay before it makes the list.)

[Puzzle-Peter]

Originally Posted by Flatlander

Now that finding the world's biggest twin is (realistically) out of my reach, I decided to set myself a different challenge.

Thus:
23321624*3^53005+-1 is twin.

Buzz Aldrin was described by David Letterman as 'The first man named Buzz to walk on the moon.' Well, this is the world's biggest twin not of the form k*2^n+-1.

Funny idea! I decided to give it a try and after quite a number of CPU cycles I came up with

22835841624*7^54321+-1 is twin

[rajula]

Originally Posted by Puzzle-Peter

22835841624*7^54321+-1 is twin

Congratulations!
That's a nice twin. It also looks nice on its place as 7th largest twin (among all those dull power-two twins)!

[Flatlander]

Originally Posted by Puzzle-Peter

Funny idea! I decided to give it a try and after quite a number of CPU cycles I came up with

22835841624*7^54321+-1 is twin

Wow! That's much bigger. How long did it take?

[Puzzle-Peter]

Originally Posted by Flatlander

Wow! That's much bigger. How long did it take?

It took about 1.7M tests, each one about 80-140 seconds, depending on the machine. Plus a week of sieving on one quad.

I guess I was lucky. I had a minus prime each 1900 tests. So I expected 1900*1900~3.5M tests, but needed only half of that.