[URL="http://www.factordb.com/index.php?id=1100000000291745056"]10^3121*5-49[/URL] -> N-1
[URL="http://www.factordb.com/index.php?id=1100000000006756989"](10^3205*28+17)/297[/URL] -> N-1

Already had factors, needed N-1 clicked:
[URL="http://www.factordb.com/index.php?id=1000000000030753225"](10^3201*14-11)/3[/URL]
[URL="http://www.factordb.com/index.php?id=1100000000014468595"](10^3228*22-1)/21[/URL]

I'm surprised that I'm still finding these in the PRP list

[URL="http://factordb.com/index.php?id=1100000000439187013"](2716^757-1)/2715[/URL] -> N-1
[URL="http://factordb.com/index.php?id=1100000000439187019"](415^991-1)/414[/URL] -> N-1

17944*36^340-1
17944*36^1716-1
17944*36^2666-1
17944*36^2838-1

In base-36, they look like this: DUFZZZZZZ....ZZZ.

[QUOTE=Stargate38;362065]17944*36^340-1
17944*36^1716-1
17944*36^2666-1
17944*36^2838-1

In base-36, they look like this: DUFZZZZZZ....ZZZ.[/QUOTE]



So then ... base-6 is:

(..340..) base36 digits 343 & base6 digits 686 ( 21502455..55 )
(..1716) base36 digits 1719 & base6 digits 3438
(..2666..) base36 dgts 2669 & base6 dgts 5338
(..2838..) base36 dgts 2841 & base6 dgts 5682



:cmd:

[URL="http://factordb.com/index.php?id=1100000000318267549"](2^9241*3+1)/7[/URL] N-1
[URL="http://factordb.com/index.php?id=1100000000035419560"](10^2785*68-23)/657[/URL] N-1

[URL="http://factordb.com/index.php?id=1100000000501424308"](2000485^512+1)/2[/URL] N-1
[URL="http://factordb.com/index.php?id=1100000000520175202"]81^1696-80[/URL] N-1

[QUOTE=wblipp;363565]" .. (81^1696-80 ..[/QUOTE]

absolutely [B][I][COLOR="Red"]do not ask to see[/COLOR][/I][/B] the "[SPOILER]other information[/SPOILER]" to ...

[URL="http://factordb.com/index.php?id=1100000000439186874"](5102^1201-1)/5101[/URL] needed more help. Fortunately, Andy Steward had already found enough factors [URL="http://www.primes.viner-steward.org/andy/titans.html"](#241)[/URL]. I was surprised to find there are still primes with over 33% factorizatization known to Andy that are unproven in factordb.

Hello,

How much of N+1/N-1 needs to be factored to prove a prime? 10^2208*106+2^7333-1 has N+1 30% factored, but that does not seem to be enough.

Chris

A third is sufficient. There are other algorithms that can be used in some cases lower than 28%.

The [URL="http://groups.yahoo.com/neo/groups/primeform/files/KP/"]Konyagin-Pomerance algorithm[/URL] (KonPom.gp) will handle 30%. For 25%+[tex]\epsilon[/tex] you can use [URL="http://primes.utm.edu/bios/page.php?id=797"]John Renze's Coppersmith-Howgrave-Graham PARI script[/URL] (CHG.GP)