20200621, 19:22  #1  
Sep 2017
USA
3·59 Posts 
Testing numbers that end in a straight sequence.
Quote:


20200623, 21:39  #2  
"TF79LL86GIMPS96gpu17"
Mar 2017
US midwest
1011111100010_{2} Posts 
Quote:
Just between the current first test milestone 90M and 200M there are two 7digit straights * and 11 more 6digit 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 7digit straight prime exponents in 200M to 1000M. There are also two 8digit straights in decimal prime exponents p, 2<p<10^{9}. 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 9digit decimal straight exponent, since consecutive decimal digits in groups of 3n are 0 mod 3. Last fiddled with by kriesel on 20200623 at 21:48 

20200627, 02:16  #3  
Sep 2017
USA
3×59 Posts 
Quote:


20200627, 12:53  #4  
"TF79LL86GIMPS96gpu17"
Mar 2017
US midwest
17E2_{16} Posts 
Quote:
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 8straight) 102354563 nf 74 (shuffled 7straight) 102354667 nf 74 (shuffled 8straight) 102354697 nf 74 (shuffled 8straight) 102356041 nf 74 (shuffled 7straight) 102356237 factored (shuffled 8straight) etc I think 9straights 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 20200627 at 13:37 

20200627, 17:00  #5  
Sep 2017
USA
B1_{16} Posts 
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20200627, 18:03  #6  
"TF79LL86GIMPS96gpu17"
Mar 2017
US midwest
1011111100010_{2} Posts 
Quote:
P1 on 113M is done and reported, 119M will take ~4 hours yet. 

20200627, 22:59  #7 
"TF79LL86GIMPS96gpu17"
Mar 2017
US midwest
2×3×1,019 Posts 
M119456789 P1 done and reported. NF for this one either.

20200628, 18:15  #8  
Sep 2017
USA
3·59 Posts 
Quote:
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. 

20200629, 01:12  #10 
"TF79LL86GIMPS96gpu17"
Mar 2017
US midwest
2·3·1,019 Posts 
To further widen this thread's scope, consider any exponent that would resemble a good poker hand. Call it poker primes.

20200629, 06:51  #11  
Undefined
"The unspeakable one"
Jun 2006
My evil lair
2×3,167 Posts 
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