New generalized Woodall record
- I'm happy to announce the finding of the new largest
generalized Woodall prime:
401208*3^401208-1 is prime! 191431 digits.
On the Top-5000 list it appears as 133736*3^401209-1.
I began searching for gen Woodall's sometime in spring 2003.
My initial objective was to find primes for "primeless" bases
and I began with b=13 but it turned out to be an unlucky choice
as in the 50,000-230,000 range I found no primes. Later, while
searching other bases I found myself often in the new record
territory but the current (now old!) record set by Wolter was
just too large to beat.
By the way, for b<=120 there are still no known gen Woodall's
in bases 13, 43, and 104 although all three are extensively
On this occasion I'd like to thank Steven Harvey for flawlessly
running "Gen Woodall" project, Mark Rodenkirch for his great
Multisieve, Jim Fougeron et al. for maintaining pfgw (not the
fastest but certainly the most reliable software to use with
this kind of primes) and last but not least George Wolter for
urging me to keep on trying to break his record!
- Of course it's Thomas Wolter, not George, who owned the old
generalized Woodall record.
Thomas, please forgive me for such an error.
--- In firstname.lastname@example.org, "pminovic" wrote:
> and last but not least George Wolter for
> urging me to keep on trying to break his record!
- On Nov 8, 2004, at 11:05 AM, pminovic wrote:
> I'm happy to announce the finding of the new largestCongrats. I only wish base 2 would be so fruitful...
> generalized Woodall prime:
> 401208*3^401208-1 is prime! 191431 digits.
> On the Top-5000 list it appears as 133736*3^401209-1.