--- In primenumbers@yahoogroups.com, "jbrennen" <jack@b...> wrote:
> Can anybody find a value of k which yields more twin primes than
> k=202507305 (3*5*7*11*13*13487) ?
>
> When k=202507305, k*2^n+/-1 are twin primes for n:
>
> 2, 12, 17, 28, 31, 33, 42, 55, 62, 86, 89, 91
>
> (and most likely for no other values of n)
>
> At the time that I found this one, I remember searching far and
> wide for a "better" k with more than 12 twin primes, with no luck.
>
> If you find a value of k with more than 12 twin primes, please
> let me know!

Jack

This goes to show it sometimes takes a while to reply to posts, in
this case 2 1/2 years!

In any case the following k has 13 twins to n=10000

7985650262654529465

And the twins are n=1,3,17,37,38,39,70,97,485,556,561,1082,1086

So there is a nice bitwin length 3 in there are well.

This resulted in a new search I have started to determine highest
scoring k.2^n+ & - 1 series, where 1 point is awarded for each twin
or cunningham chain length 2. (a CC length 3 gets two points, etc).

The k quoted has 13 twins, and 15 points for cunningham chains (up
to n=10000), so 28 is a nice easy target to beat.

Regards

Robert Smith