Reserved for MF - Sequence 4788 - Page 255

science_man_88 · 2016-12-23, 16:33

Quote:

Originally Posted by Drdmitry

The driver has been lost again.
This song will play forever. :)

too bad all it will take for it to be a driver again ( okay 2^3 is a guide technically) is gaining a 5 or a 3. this is a better link potentially if you don't want to look up the whole sequence and just see the last line.

Drdmitry · 2016-12-23, 16:42

Quote:

Originally Posted by science_man_88

too bad all it will take for it to be a driver again ( okay 2^3 is a guide technically) is gaining a 5 or a 3. this is a better link potentially if you don't want ot look up the whole sequence and just see the last line.

2³ without a factor of 5 or 3 is not a guide. It will be stable until the power of two changes.

science_man_88 · 2016-12-23, 16:44

Quote:

Originally Posted by Drdmitry

2³ without a factor of 5 or 3 is not a guide. It will be stable until the power of two changes.

http://www.rechenkraft.net/aliquot/analysis.html list it as a class 3 guide it may not class as a driver though.

Dubslow · 2016-12-23, 17:48

Quote:

Originally Posted by Drdmitry

2³ without a factor of 5 or 3 is not a guide. It will be stable until the power of two changes.

In SM_88's link, I followed Clifford Stern's definition:

Quote:

A guide consists of $2^a$ ($a \gt 0$) along with a subset of the prime factors of $\sigma(2^a)$.

I interpreted it in the following way, which I believe to be at least perfectly reasonable if really just a question of meaningless semantics.

Quote:

This motivates the following definition: a number of the form 2^b \cdot v, where v divides \sigma(2^b), is called a guide. (Note that when v=1, the guide is just the power of 2.)

Actually, technically by your statement the down"driver" wouldn't be considered a guide. I think that is certainly enough to justify the empty powers of two as guides also...

ryanp · 2016-12-24, 00:42

Maybe it's time to change my username to Sisyphus...

LaurV · 2016-12-24, 02:58

Quote:

Originally Posted by ryanp

Maybe it's time to change my username to Sisyphus...

Told you so... Trust the Old Salt next time...

Now, don't be sad, from how the graph looks like, we may find the first cycle in the history of man, with a period 7000 or so...

VBCurtis · 2017-01-03, 23:20

Ugh. The 7.

LaurV · 2017-01-06, 12:23

good, now it is me again who owns the largest downdriver!

(which is 613068, at 153 digits, not yet updated into Dubslow's table)

Batalov · 2017-01-06, 15:26

Well, don't get your hopes too low!

ryanp · 2017-01-07, 01:37

Quote:

Originally Posted by Batalov

Well, don't get your hopes too low!

Except that we're rapidly approaching 200 digits...

Need that downdriver ASAP.

unconnected · 2017-02-22, 09:43

No progress from Jan 18, did Ryan still working on it?

2017-01-06, 12:23	#2802
LaurV Romulan Interpreter "name field" Jun 2011 Thailand 3×23×149 Posts	good, now it is me again who owns the largest downdriver! (which is 613068, at 153 digits, not yet updated into Dubslow's table) Last fiddled with by LaurV on 2017-01-06 at 12:24 Reason: s/155/153/ tyop

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