20120810, 11:18  #34  
Mar 2006
Germany
2846_{10} Posts 
Quote:
Code:
Mers Expo start in PI at digit 2 6 3 9 5 4 7 13 13 110 17 95 19 37 31 137 61 219 89 11 107 1487 127 297 521 172 607 286 1279 11307 2203 1910 2281 19456 3217 959 4253 7337 4423 7591 9689 690 9941 1073 11213 47802 19937 115211 21701 28507 23209 280538 44497 85342 86243 89373 110503 808004 132049 840293 216091 3226144 756839 996061 859433 2887812 1257787 24078017 1398269 2037623 2976221 20104152 3021377 1220576 6972593 9252419 13466917 39603620 20996011 40909479 24036583 8854005 25964951 19456503 30402457 645842094 32582657 510029176 37156667 53909580 42643801 228338527 43112609 248103197 Mersenne expo 127 starts at index 297 which is 129_{16}. 

20120810, 14:52  #35 
"Mike"
Aug 2002
7704_{10} Posts 
What is the largest known prime in the sequence of digits of pi?

20120810, 21:36  #36 
"Forget I exist"
Jul 2009
Dumbassville
2^{6}·131 Posts 
http://oeis.org/A060421 supposedly shows that one known one is up to over 78000 digits depending on how you define a pi prime

20120814, 14:32  #37  
May 2004
New York City
2·3^{2}·5·47 Posts 
Quote:
are going to or have already exceeded that. 

20120814, 17:01  #38 
"Serge"
Mar 2008
Phi(4,2^7658614+1)/2
2×3^{3}×13^{2} Posts 
I've halfheartedly tried to check the same run up from 78073 to 100k (and the a(20) and a(96) to 100k)  no primes (and then the run gets slow), so prp78073 holds the palm d'or as far as we know. It can be easily beaten with random starts and in the range of lengths from 78074 to 8085k, but that would be fairly pointless  that in turn would be easily beaten.

20120814, 19:27  #39  
May 2004
New York City
2·3^{2}·5·47 Posts 
Quote:
(Don't want to light any fires, but breaking records is always fun.) 

20120816, 13:31  #40  
May 2004
New York City
2×3^{2}×5×47 Posts 
Quote:
motivation? I would love to know the length of the values for 20 amd 96. 

20120816, 16:26  #41 
"Serge"
Mar 2008
Phi(4,2^7658614+1)/2
2·3^{3}·13^{2} Posts 
They are longer than 103,000 digits. :)

20120817, 00:26  #42 
May 2004
New York City
2×3^{2}×5×47 Posts 

20120817, 04:34  #43 
Bemusing Prompter
"Danny"
Dec 2002
California
2^{8}×3^{2} Posts 
Because pi has an infinite number of digits, it's almost certain that every possible sequence can be found. I wonder how far one will have to go in order to find, say, M#47?
Last fiddled with by ixfd64 on 20120817 at 04:50 
20120821, 16:52  #44 
"Serge"
Mar 2008
Phi(4,2^7658614+1)/2
2×3^{3}×13^{2} Posts 
a(96) = 140,165digit PRP
Well, ok, records are made to be broken. With a bit of luck I found a 140,165digit PRP that starts with the first "96" in Pi, the a(96). This may also be the largest known PRP in the sequence of digits of Pi, for Xyzzy.
I Code:
# Pari/GP # \p 143000 prp=floor(Pi*10^140344)%10^140165; # passes the GP ispseudoprime(prp) test, too, in addition to PFGWbased PRP and BLS EDIT2: strictly speaking, because a(96) is quite big  it may not be a minimal solution: there's a chance that by way of some bug I could have missed some smaller PRP (I also have a small gap between two threads that processed candidates above and below 125,000 digits, which I will close sometime soon; I may rerun the whole search using a different base for PRP, too  or anyone else is welcome to. The scripts are all here, in this thread.) Last fiddled with by Batalov on 20120821 at 19:03 
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