- Thanks.

Currently I am hunting for a 31 digit CC15 (2nd kind). After 40 hours

of 29 computers work I have 2 CC14:

CC14, 2nd kind: 2354904873485081880414653783011 (31 digits)

CC14, 2nd kind: 756623498046318886601149174501 (30 digits)

and 21 CC13 in 30-32 digits, with the top 3 being:

CC13, 2nd kind: 71893041796676884721115682595521 (32 digits)

CC13, 2nd kind: 71183625845277875816974563041281 (32 digits)

CC13, 2nd kind: 61769341861507223234745310908481 (32 digits)

Jarek

2008/6/14, Dirk Augustin <Dirk_Augustin@...>:> --- In primenumbers@yahoogroups.com, "jarek372000"

> <Jaroslaw.Wroblewski@...> wrote:

>>

>> I have discovered:

>>

>> CC16, 2nd kind: 20193491108493165642344881 (26 digits)

>> CC15, 2nd kind: 71838292723844326926417601 (26 digits)

>>

>> Jarek

>>

>

> Congratulations for improving the CC15 and CC16 records by another

> digit!

>

> Finally I managed to update the record list in the Files section. Jens

> Kruse Andersen will update the corresponding web page.

>

> Regards,

> Dirk

>

>

>

> ------------------------------------

>

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> The Prime Pages : http://www.primepages.org/

>

> Yahoo! Groups Links

>

>

>

> - After over 9 days of 30 computers work I have discovered:

CC16, 2nd kind: 2368823992523350998418445521 (28 digits)

It has 30 digit 8th term:

303209471042988927797561026561

which is responsible for 16 Simultaneous Primes score.

I am resending this message as the previous one seems to have been

corrupted. My apologies if you get it twice.

Jarek - Jarek wrote:
> CC16, 2nd kind: 2368823992523350998418445521 (28 digits)

Congratulations on your sixth improvement of this record in a month:

>

> It has 30 digit 8th term:

>

> 303209471042988927797561026561

>

> which is responsible for 16 Simultaneous Primes score.

http://hjem.get2net.dk/jka/math/simultprime.htm#history16

--

Jens Kruse Andersen - I have found a new record for 15 Largest Known Simultaneous Primes:

CC15 (1st kind, 41 digit first term):

27353790674175627273118204975428644651730*2^n-1, n=0..14

(Apr 25, 2014, Jaroslaw Wroblewski)

43 digit 8-th term 3501285206294480290959130236854866515421439

I applied a litlle trick, namely created and used polynomial

P(x) = 86730930*x^2,

which has nice property of having over-average density of Cunningham Chains

P(x)*2^n-1

The above Cunningham Chain is obtained for

x=17759132926784169, so it can also be written as

86730930*17759132926784169^2 * 2^n - 1, n=0..14

The search was very lucky (only one CC13 and the above CC15 was found)

and short (2 hours of 60 threads).

Jarek