Prime posting thread, part 2. (With a catch.) - Page 5

CRGreathouse · 2010-11-05, 15:51

Quote:

Originally Posted by Batalov

This one contains 11, though. If the substring condition is dropped, then it will be hard to beat 10²³²⁵⁹⁹-3 and 5·10²¹¹⁰²⁹-1

I don't know how I managed to do that -- I thought I had checked for all substrings of lenght 2 or greater. (Obviously not!) I have a list of candidates to check; I'll try to give the smallest in a bit.

Batalov · 2010-11-05, 18:37

Note that the 499...999 number was found yesterday by David Broadhurst... and after that, immediately, another one (899...999):
9·10²¹²⁹⁰³-1
Nice!

Interestingly, also last week after years of dormancy, the PWP project reported this 999...9992999...999 number. All three have substrings though: 499, 89, 29, so they are only interested in the 'unrestricted' sence.

mdettweiler · 2010-11-14, 19:28

9996*10^81902-1 is prime! (proven by LLR with an N+1 test)

It is of the form 999599999999....[all 9's].

3.14159 · 2010-11-14, 21:15

Quote:

Originally Posted by mdettweiler

9996*10^81902-1 is prime! (proven by LLR with an N+1 test)

It is of the form 999599999999....[all 9's].

Nice!

Batalov · 2010-11-14, 21:28

Quote:

Originally Posted by mdettweiler

9996*10^81902-1 is prime! (proven by LLR with an N+1 test)

It is of the form 999599999999....[all 9's].

...has 59 substring...

CRGreathouse · 2010-11-14, 21:36

Quote:

Originally Posted by Batalov

...has 59 substring...

And 599, 59999, 599999, 59999999, 59999999999, 59999999999999, 59999999999999999999999, 599999999999999999999999, 59999999999999999999999999999, 59999999999999999999999999999999999, 59999999999999999999999999999999999999999, 59{61 9s in total}9, 59{73 9s in total}9, 59{361 9s in total}9, 59{490 9s in total}9, 59{613 9s in total}9, 59{1624 9s in total}9, ...

Batalov · 2010-11-18, 00:38

100001001*10^50476+1 is a suitable prime

3.14159 · 2010-11-18, 00:56

Quote:

Originally Posted by Batalov

100001001*10^50476+1 is a suitable prime

As long as it steers clear of 11, or 101.

CRGreathouse · 2010-11-18, 00:59

Quote:

Originally Posted by 3.14159

As long as it steers clear of 11.

Well... it does...

Batalov · 2010-11-19, 22:14

Upping the stakes, ever so lightly...

100010001*10^81741+1 is a prime.

3.14159 · 2010-11-19, 22:55

Quote:

Originally Posted by Batalov

Upping the stakes, ever so lightly...

100010001*10^81741+1 is a prime.

Prove it.

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Thread for posting tiny primes	3.14159	Miscellaneous Math	947	2021-02-13 08:40
PLEASE READ BEFORE POSTING!	ewmayer	Information & Answers	1	2019-04-05 03:13
The Prime Announcement Thread	axn	Sierpinski/Riesel Base 5	61	2008-12-08 16:28
The 100,000th posting	cheesehead	Forum Feedback	1	2007-03-06 15:33
PLEASE READ BEFORE POSTING!	ewmayer	Lounge	0	2006-04-12 18:48

2010-11-05, 18:37	#46
Batalov "Serge" Mar 2008 Phi(4,2^7658614+1)/2 9,497 Posts	Note that the 499...999 number was found yesterday by David Broadhurst... and after that, immediately, another one (899...999): 9·10²¹²⁹⁰³-1 Nice! Interestingly, also last week after years of dormancy, the PWP project reported this 999...9992999...999 number. All three have substrings though: 499, 89, 29, so they are only interested in the 'unrestricted' sence.

2010-11-14, 19:28	#47
mdettweiler A Sunny Moo Aug 2007 USA (GMT-5) 3×2,083 Posts	9996*10^81902-1 is prime! (proven by LLR with an N+1 test) It is of the form 999599999999....[all 9's].

2010-11-18, 00:38	#51
Batalov "Serge" Mar 2008 Phi(4,2^7658614+1)/2 9,497 Posts	100001001*10^50476+1 is a suitable prime

2010-11-19, 22:14	#54
Batalov "Serge" Mar 2008 Phi(4,2^7658614+1)/2 9,497 Posts	Upping the stakes, ever so lightly... 100010001*10^81741+1 is a prime.