fond of a factor? Urn yourself to become remains

[chalsall]

Originally Posted by Thecmaster

I have just started and found a factor on my 8 TF :D

Congratulations! And welcome.

Just so you know, you have been statistically "lucky" with this find. On average, you will find approximately one factor per 1/[bit level] where P-1'ing hasn't yet been done. Where P-1'ing has already been done (read: DCTF'ing) the success rate will be lower.

The reason I bring this up is please don't be discouraged if you don't find another factor for a while. Statistics has no memory, so every TF'ing run has the same probability of finding a factor, regardless of how "lucky" or "unlucky" you have been in the past. Run an infinite number of tests, and you will converge on the expected number of finds (assuming your kit is good).

P.S. Just to share, I personally use my (slow) GPUs to help Wayne's "to below 2,000" sub-sub-project. It took 426 (!) TF'ing runs from 71 to 72 bits to finally find this factor, and get 33.9 to below 2,000 un-factored candidates.

[petrw1]

Originally Posted by chalsall

P.S. Just to share, I personally use my (slow) GPUs to help Wayne's "to below 2,000" sub-sub-project. It took 426 (!) TF'ing runs from 71 to 72 bits to finally find this factor, and get 33.9 to below 2,000 un-factored candidates.

All are welcome :)

https://www.mersenneforum.org/showthread.php?t=22476

[LaurV]

Originally Posted by chalsall

On average, you will find approximately one factor per 1/[bit level]

Are you sure? hihi That would be nice to have more factors than trials...

I though you find one factor in [bitlevel] tries.

Or my Englsih plays tricks to me? hihi

[lycorn]

Originally Posted by LaurV

Or my Englsih plays tricks to me? hihi

Your Englsih is certainly playing tricks on you... the English I don´t know.

[chalsall]

Originally Posted by LaurV

Are you sure? hihi

You're correct; I misspoke...

I should have said "your probability of finding a factor is approximately 1/[bit level], or one every [bit level] runs"....

[penlu]

M92617193 is divisible by 1175619298002469430597399521162713999664087. This 139.75-bit factor brought to you by P-1.

[Thecmaster]

Some luck here. One more factor.

M55303189 has a factor: 18522127152677986447913 [TF:73:74:mfaktc 0.21 barrett76_mul32_gs]
found 1 factor for M55303189 from 2^73 to 2^74 [mfaktc 0.21 barrett76_mul32_gs]

[Jwb52z]

UID: Jwb52z/Clay, M90939509 has a factor: 10728673174057307870137591 (P-1, B1=685000)

83.150 bits.

[Jwb52z]

P-1 found a factor in stage #1, B1=685000.
UID: Jwb52z/Clay, M90969559 has a factor: 36906292085934351166387681 (P-1, B1=685000)

84.932 bits.

[Miszka]

Today I found my largest composite factor 19147642464835832222111776488276027610060674573088897824886038321359 (223.5 bits - 68 digits) =82139596673583394582617549419848961 * 233110987151874257840851425095119 for the number of M3146833.

[James Heinrich]

Impressive. Even the two component factors are quite respectable in their own rights (108, 116 bits).