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Old 2017-11-26, 23:10   #12
sweety439
 
Nov 2016

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Quote:
Originally Posted by sweety439 View Post
Reserve 305^n-2 to n=20000.
305^n-2 tested to n=20000, no (probable) prime found.

Reserve it to n=30000.
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Old 2017-12-01, 21:56   #13
sweety439
 
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305^n-2 tested to n=30000, no (probable) prime found.

Base released.
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Old 2020-12-23, 23:56   #14
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In fact, if x*y = b, then

x*b^n+1 is the dual of y*b^n+1
x*b^n-1 is the dual of y*b^n-1
(x*b^n+1)/gcd(x+1,b-1) is the dual of (y*b^n+1)/gcd(y+1,b-1)
(x*b^n-1)/gcd(x-1,b-1) is the dual of (y*b^n-1)/gcd(y-1,b-1)

Thus they have the same weight
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Old 2021-02-15, 15:58   #15
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Since 2293*2^12918431-1 is known to be prime (see post https://mersenneforum.org/showpost.p...&postcount=895), the only 4 remain odd k<509203 with neither known prime of the form k*2^n-1 nor known (probable) prime of the form |2^n-k| are 342847, 344759, 386801, 444637

Also, the "mixed Sierpinski conjecture base 5" is now a theorem (in the weak case that probable primes are allowed), see thread https://mersenneforum.org/showthread.php?t=26328, the only even k<159986 not divisible by 5 with neither known prime of the form k*5^n+1 nor known proven prime of the form 5^n+k is 31712, and there is known probable prime for k=31712: 5^50669+31712
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