Timeline for Multiplicative Persistence - Highest persistence found? [closed]
Current License: CC BY-SA 4.0
27 events
| when toggle format | what | by | license | comment | |
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| Oct 3, 2023 at 17:07 | comment | added | YCor | One more decimal-sensitive artificial definition... | |
| Oct 1, 2023 at 17:08 | comment | added | Jukka Kohonen | @Gerald: Yes, OEIS accepts large numbers in so-called b-files; the guideline says the lines in the file should not "generally" exceed 1000 characters, so ~500 digits would be fine. But there is no reason to believe that this supposed number would belong to A003001; even if it has persistence 12 (which already seems unlikely), there is nothing to suggest it would be the smallest such number, and that's what A003001 is supposed to contain. | |
| Oct 1, 2023 at 16:53 | comment | added | Gerald Edgar | I wonder if one can submit such a large number to oeis.org/A003001 ... items submitted to OEIS are checked by someone before being accepted. | |
| Sep 30, 2023 at 12:47 | history | undeleted | Stefan Kohl♦ | ||
| Sep 29, 2023 at 21:57 | review | Reopen votes | |||
| Sep 29, 2023 at 22:07 | |||||
| Sep 29, 2023 at 20:37 | review | Reopen votes | |||
| Sep 29, 2023 at 20:41 | |||||
| Sep 29, 2023 at 10:09 | review | Reopen votes | |||
| Sep 29, 2023 at 10:15 | |||||
| Sep 29, 2023 at 9:57 | history | deleted | Stefan Kohl♦ | via Vote | |
| Sep 29, 2023 at 6:01 | history | closed |
LSpice Joseph Van Name abx Max Horn Dave Benson |
Not suitable for this site | |
| Sep 29, 2023 at 2:30 | comment | added | Sidharth Ghoshal | @mwt2212 do you want to just post the number here? It’s simple enough to check and you have now piqued my curiosity | |
| Sep 29, 2023 at 1:58 | answer | added | Jukka Kohonen | timeline score: 12 | |
| Sep 29, 2023 at 1:56 | comment | added | LSpice | Re, if you are not familiar with the arXiv, then please study it very carefully before submitting. If you do not have a university affiliation, then you will probably have best luck with your submission being accepted if you have an endorsement, for example, from a math professor with whom you have discussed your work. If you do not have such a person yet, then it is probably more appropriate to build such a relationship and discuss there than to submit to the arXiv. | |
| Sep 29, 2023 at 1:31 | comment | added | mwt2212 | Double checked it with a handful of others code that's been posted online for this. Definitely 12, not even sure how I would go about proving it's the smallest one unless I was gonna brute force numbers up to ~500 digits (lol). Not sure what arXiv is, but tomorrow when I wake up I'll check it out and see what they think. Thanks guys | |
| Sep 29, 2023 at 0:56 | comment | added | LSpice | @SidharthGhoshal, re, I think the arXiv folks would probably frown on the use of the arXiv as a proof checker / "challenge" site. | |
| Sep 29, 2023 at 0:30 | comment | added | mwt2212 | @SidharthGhoshal Just tried that out for fun lol, goes to 0 after 1 step as if you get a number with a zero in it anywhere, the process will always terminate on the next step. But also, no, I do not have proof this is the smallest such number, just a such number. As far as I look online, nobody has found any number with a persistence of 12, so I doubt this is the smallest one as well. | |
| Sep 29, 2023 at 0:15 | history | edited | Sidharth Ghoshal |
edited tags
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| Sep 29, 2023 at 0:13 | comment | added | Sidharth Ghoshal | Is it just an arbitrary number or do you have a proof its the smallest such number? Because I could easily make high persistence by say consider a number of just 1,000 digits of 9 and then measuring its persistence (it would be large). Actually, you should just post it on ArXiV and see if anyone manages to beat it as a quick way of checking | |
| Sep 29, 2023 at 0:11 | comment | added | mwt2212 | Yeah I've seen that post. Number I found has 500 digits ^. Still don't know how to send direct replies @SidharthGhoshal | |
| Sep 29, 2023 at 0:11 | review | Close votes | |||
| Sep 29, 2023 at 6:02 | |||||
| Sep 29, 2023 at 0:09 | comment | added | Sidharth Ghoshal | and this individual if they are to be believed says they could not find a number with less than 400 digits: reddit.com/r/numberphile/comments/b5ognh/… here is a link to their code github.com/Davipb/MultiplicativePersistence from that same reddit post are you somehow searching numbers beyond 400 digits in length? | |
| Sep 29, 2023 at 0:09 | comment | added | Sidharth Ghoshal | Multiplicative Persistence is defined here: mathworld.wolfram.com/…. I would be shocked that it has a finite bound, it just appears that it takes very very large numbers to move the persistence needle. In this case the wolfram article suggests that there is no number with less than 233 digits and this individual if they are to be believed says they could not find a number with less than 400 digits: | |
| Sep 28, 2023 at 23:59 | comment | added | mwt2212 | Still no idea if this comment is notifying you as a reply, or just a standard comment, but I pushed enter trying to go to next line earlier, I meant to explain in my original reply, my bad. ^ Edited first comment. | |
| Sep 28, 2023 at 23:56 | comment | added | LSpice | Re, as I have just indicated, once you say what your terms mean, this might do better on MSE. Or it is possible that it will be appropriate for MO, but it's impossible to say unless you define multiplicative persistence. | |
| Sep 28, 2023 at 23:56 | comment | added | mwt2212 | Not sure if this reply button is replying to you or my post in general, but yeah sorry about that. Just don't know where else to ask. Multiplicative persistence as in, multiply every digit in a number by each other, how many steps to reach a single digit number. Highest persistence I can see found online is 11. So the code is just taking a number and multiplying the digits together until > 10. Pretty hard to believe there would be a bug in the code since it's so simple, but yeah. Sorry about not explaining. | |
| Sep 28, 2023 at 23:54 | comment | added | LSpice | What is "multiplicative persistence"? Why would it be a bug if running code (what code?) on numbers with known persistence outputs the expected result? \\ Also, MO is for research-level mathematics, not as a replacement for being unable to post to r/math. You might have better luck at our sister site MSE, once you clarify your terms. (Also also—unless you just want to advertise, which is not appropriate here or on MSE—once you define what multiplicative persistence is, you should give the number you think brings it to 12.) | |
| S Sep 28, 2023 at 23:52 | review | First questions | |||
| Sep 29, 2023 at 2:27 | |||||
| S Sep 28, 2023 at 23:52 | history | asked | mwt2212 | CC BY-SA 4.0 |