mersenneforum.org Testing numbers that end in a straight sequence.
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2020-06-21, 19:22   #1
Runtime Error

Sep 2017
USA

20010 Posts
Testing numbers that end in a straight sequence.

Quote:
 Originally Posted by kriesel No problem and thanks for helping. The numbers listed in post 20 are stated in post 28 as coming from the sort of source or process that sounds more like conspiracy theory than number theory. So I see no reason to give them any priority now. It did no harm to trial factor them somewhat, a little early. I feel it's more productive to return to our usual mostly systematic searching in exponent order, than to give these few any extra attention. That's all.
Conspiracy theory or not, I'm testing 160456789 because I like that it ends in 4,5,6,7,8,9. But 369452123 is definitely not on my list.

2020-06-23, 21:39   #2
kriesel

"TF79LL86GIMPS96gpu17"
Mar 2017
US midwest

10110000111102 Posts

Quote:
 Originally Posted by Runtime Error I'm testing 160456789 because I like that it ends in 4,5,6,7,8,9.
Have fun.

Just between the current first test milestone 90M and 200M there are two 7-digit straights * and 11 more 6-digit straights in prime exponents' decimal forms. Five of which are both insufficiently factored now and have no factors found yet or primality tests completed.
92456789 (factored)
103456789* (factored, and half the digits of its factor are the digit 6)
106456789 (factored)
113456789* NF 73, assigned
116456789 (factored)
119456789 NF 72
130456789 NF 72
137456789 (factored)
154456789 (factored)
167456789 NF 75
170456789 NF 73
179456789 (factored)
182456789 (factored)
There are probably more 6 and 7-digit straight prime exponents in 200M to 1000M.

There are also two 8-digit straights in decimal prime exponents p, 2<p<109.
23456789 (factored)
623456789 NF 71 (assigned)

Descending straights are also present
98765431 prime exponent shown LLDC composite
198765439 NF 74
198765433 factored
876543211 NF 80
987654323 NF 76
765432131 factored
765432163 NF 71
765432169 factored
765432179 NF 71
765432197 factored
etc.

There is no prime 9-digit decimal straight exponent, since consecutive decimal digits in groups of 3n are 0 mod 3.

Last fiddled with by kriesel on 2020-06-23 at 21:48

2020-06-27, 02:16   #3
Runtime Error

Sep 2017
USA

23·52 Posts

Quote:
 Originally Posted by kriesel Have fun. Just between the current first test milestone 90M and 200M there are two 7-digit straights * and 11 more 6-digit straights in prime exponents' decimal forms. Five of which are both insufficiently factored now and have no factors found yet or primality tests completed. 92456789 (factored) 103456789* (factored, and half the digits of its factor are the digit 6) 106456789 (factored) 113456789* NF 73, assigned 116456789 (factored) 119456789 NF 72 130456789 NF 72 137456789 (factored) 154456789 (factored) 167456789 NF 75 170456789 NF 73 179456789 (factored) 182456789 (factored) There are probably more 6 and 7-digit straight prime exponents in 200M to 1000M. There are also two 8-digit straights in decimal prime exponents p, 2
Neat! Thanks for posting this fun list. I just reserved the two smallest unfactored, 113456789 and 119456789. I saw that you recently did some factoring work on the former. If you are still working on it, it's yours (just please let me know to stop).

2020-06-27, 12:53   #4
kriesel

"TF79LL86GIMPS96gpu17"
Mar 2017
US midwest

566210 Posts

Quote:
 Originally Posted by Runtime Error Neat! Thanks for posting this fun list. I just reserved the two smallest unfactored, 113456789 and 119456789. I saw that you recently did some factoring work on the former. If you are still working on it, it's yours (just please let me know to stop).
You have the PRP assignments. I've taken the liberty of launching P-1 on both those. If you are already running or have run P-1 to adequate bounds, let me know, and I'll halt the runs. What I've queued on an RX480 are
B1=1170000,B2=33930000;PFactor=0,1,2,113456789,-1,76,2 (running now)
B1=1250000,B2=36250000;PFactor=0,1,2,119456789,-1,76,2
If I hit a factor I'll let you know.

Otherwise, carry on.
BTW https://www.mersenne.org/report_expo...9456789&full=1 needs more TF also, now at 72 bits, 76 recommended.

The availability of straights is increased if also considering shuffled straights, not only ordered straights as in my earlier message.
102354367 factored (shuffled 8-straight)
102354563 nf 74 (shuffled 7-straight)
102354667 nf 74 (shuffled 8-straight)
102354697 nf 74 (shuffled 8-straight)
102356041 nf 74 (shuffled 7-straight)
102356237 factored (shuffled 8-straight)
etc
I think 9-straights are still absent, because shuffling the digits adds or subtracts multiples of 9,
and 012 345 678 is a multiple of 3, as is 123 456 789.

Last fiddled with by kriesel on 2020-06-27 at 13:37

2020-06-27, 17:00   #5
Runtime Error

Sep 2017
USA

23×52 Posts

Quote:
 Originally Posted by kriesel You have the PRP assignments. I've taken the liberty of launching P-1 on both those. BTW 119456789 needs more TF also, now at 72 bits, 76 recommended.
Thanks for the heads up. I queued both for TF to 78, and I have not started P-1 or PRP yet. I'll wait until I see your P-1 results pop up before I start PRPing. Happy hunting!

2020-06-27, 18:03   #6
kriesel

"TF79LL86GIMPS96gpu17"
Mar 2017
US midwest

2×19×149 Posts

Quote:
 Originally Posted by Runtime Error Thanks for the heads up. I queued both for TF to 78, and I have not started P-1 or PRP yet. I'll wait until I see your P-1 results pop up before I start PRPing. Happy hunting!
78 seems a bit high to me particularly since I'm going to PrimeNet P-1 bounds, but your kit, your call.
P-1 on 113M is done and reported, 119M will take ~4 hours yet.

 2020-06-27, 22:59 #7 kriesel     "TF79LL86GIMPS96gpu17" Mar 2017 US midwest 130368 Posts M119456789 P-1 done and reported. NF for this one either.
2020-06-28, 18:15   #8
Runtime Error

Sep 2017
USA

23×52 Posts

Quote:
 Originally Posted by kriesel M119456789 P-1 done and reported. NF for this one either.
Thanks, I took both to 78 but to no avail. I understand your point with full primenet bounds; next time. PRPing now.

Since this is now its own thread, perhaps a mod might consider adding a disclaimer to the first post saying that testing Mersenne exponents containing sequences is purely recreational? Just in case someone new stumbles across this and thinks there is a hidden pattern or secret formula or something. (There have been a lot of those posts.) I also enjoy testing exponents containing birthdays, anniversaries, and other things that are fun to me, but that are unlikely predictors of primality.

 2020-06-28, 23:42 #9 Jan S   Oct 2018 Slovakia 2·3·13 Posts I'll try "one shot" in this funny thread. I took 111213143 TF to 79 (>P-1, >>PRP)
 2020-06-29, 01:12 #10 kriesel     "TF79LL86GIMPS96gpu17" Mar 2017 US midwest 2·19·149 Posts To further widen this thread's scope, consider any exponent that would resemble a good poker hand. Call it poker primes.
2020-06-29, 06:51   #11
retina
Undefined

"The unspeakable one"
Jun 2006
My evil lair

23·33·29 Posts

Quote:
 Originally Posted by Runtime Error Since this is now its own thread, perhaps a mod might consider adding a disclaimer to the first post saying that testing Mersenne exponents containing sequences is purely recreational? Just in case someone new stumbles across this and thinks there is a hidden pattern or secret formula or something. (There have been a lot of those posts.) I also enjoy testing exponents containing birthdays, anniversaries, and other things that are fun to me, but that are unlikely predictors of primality.
Haha, if someone wants to believe in hidden patterns and secret formulas then let them have at it. Sometimes the cranks are the most entertaining posters.

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