fun with msieve

[michaf]

I kinda gave up on doing snfs on smarandache numbers, the coefficients just get too large to be useful. With the cyclic numbers, you get an extra c2 coefficient in it too, which gives troubles too. (Mostly like: 0 relations, very bad parameters...)

[masser]

Two more factors:

285598*5^303-1 has a factor: 4633300259237346229982505306181
96994*5^340+1 has a factor: 1790683628219730869084434903

I have completed P-1 and P+1 up to (and including) the 40 digit level for n < 400. Attached is the list of remaining candidates for n < 400.

[ValerieVonck]

Originally Posted by fivemack

I'm not certain about this, but it might help to negate both Y0 and Y1; I think the ggnfs relation-processing code might prefer Y1 to be positive. I saw a couple of crashes like this when trying to figure out the polynomials.

Ok I will try!

Thanks!

[ValerieVonck]

I tried to make the Y0 & Y1 negative.
I have the same problem... ggnfs crashes.

I get a lot of lines with "temp" in it.
Then it ends unsuccessfully.

[masser]

Originally Posted by michaf

I'll be reserving 49568*5^148-1 and 151026*5^149-1

Michaf, Did you ever complete the factorization of 151026*5^149-1? I am going to upload a new small_n.txt file soon and was curious about this smallest remaining candidate...

[michaf]

Yep... just now did :>

Number: 151026_5_149m1
N=21163250187311982295332718404594287364273284003384267094538299464273958805371478320012101903557777404785156249
( 110 digits)
SNFS difficulty: 111 digits.
Divisors found:
r1=17967537304669033082651892488518433241019125845707 (pp50)
r2=1177860372763078290543313122180844345933017104324690833300907 (pp61)
Version: GGNFS-0.77.1-20060513-athlon-xp
Total time: 1.53 hours.

Edit: also did:

Number: 227968_5_149m1
N=31945120831519989802434078564343560061569875436570554745591534254178789353773026959970593452453613281249999999
( 110 digits)
SNFS difficulty: 110 digits.
Divisors found:
r1=90186315791829811723833774311 (pp29)
r2=354212504979762934920679047521137569636698392609375294680940309621359862094679209 (pp81)
Version: GGNFS-0.77.1-20060513-athlon-xp
Total time: 1.29 hours.

[frmky]

Originally Posted by fivemack

I've found the large constant (or X^5 for the non-reverse case) coefficient distinctly troublesome for the Smarandache numbers; I set up for an attack on Sm94 thinking it would be a matter of a couple of weeks (180 digits SNFS), but couldn't find parameters which came up as less than several months relation-collection; it seems maybe even a little harder than Fib(1009), which was 210 digits but with a really convenient polynomial.

On this topic, has any progress been made on the Reverse Smarandache number rsm88? I can't find any record of it being factored. I've started sieving on it using a quad-core workstation, and based on current progress it looks like I can finish it within the week.

Greg