Generalized repunit (probable) prime search
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This thread is for finding the smallest generalized repunit (probable) prime for a fixed base b, I have searched them for all bases 2<=b<=1024 and 1024<=b<=2, see the text files. Of course, I know that there is no generalized repunit prime in base b for some bases because of the algebra factors, all such bases are either perfect powers or of the form 4k^4. Besides, I have completed these ranges:
Positive bases: b<=400 to n=50000. 401<=b<=512 to n=30000. 513<=b<=1024 to n=10000. Negative bases: b>=400 to n=50000. 512<=b<=401 to n=30000. 1024<=b<=513 to n=8000. Also, I extended these searches for some smaller base b with no (probable) prime found, for positive bases, I completed b=185 to n=66337, b=269 to n=63659 and b=281 to n=63421, and for negative bases, I completed b=97 to n=59863, b=103 to n=59509 and b=113 to n=59021, all have still no (probable) prime found. 
You could submit this information to the OEIS entries which are [URL="https://oeis.org/A128164"]A128164[/URL] and [URL="https://oeis.org/A084742"]A084742[/URL], respectively. /JeppeSN

[QUOTE=JeppeSN;487051]You could submit this information to the OEIS entries which are [URL="https://oeis.org/A128164"]A128164[/URL] and [URL="https://oeis.org/A084742"]A084742[/URL], respectively. /JeppeSN[/QUOTE]
I do not have OEIS account and not decide to create. 
How did you extend these ranges? Is there a good sieve software and fast PRP software.
If you used PFGW  what setting did you use? Thanks. 
From [URL="http://oeis.org/A028491"]OEIS A028491[/URL], Paul Bourdelais has discovered a new base3 repunit (probable) prime:
(3^2215303 − 1) /2 is a PRP The [URL="http://www.primenumbers.net/prptop/prptop.php"]Lifchitz PRP Top page[/URL] shows two other discoveries in January for bases −6 and −7: (6^1313371 + 1) /7 (7^1178033 + 1) /8 
[QUOTE=GP2;507879]From [URL="http://oeis.org/A028491"]OEIS A028491[/URL], Paul Bourdelais has discovered a new base3 repunit (probable) prime:
(3^2215303 − 1) /2 is a PRP[/quote] [COLOR="Red"]1'057,967 digits [/COLOR] 
hi,
reserving R[6] from n=608100 to 1000000 
[QUOTE=lalera;530558]hi,
reserving R[6] from n=608100 to 1000000[/QUOTE] range done. no prp found 
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