Timeline for What does this mathematical operator do?
Current License: CC BY-SA 4.0
113 events
| when toggle format | what | by | license | comment | |
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| S Oct 16 at 21:10 | history | bounty ended | ThomasL | ||
| S Oct 16 at 21:10 | history | notice removed | ThomasL | ||
| S Oct 15 at 21:09 | history | bounty started | ThomasL | ||
| S Oct 15 at 21:09 | history | notice added | ThomasL | Reward existing answer | |
| Oct 12 at 20:35 | vote | accept | PattuX | ||
| Oct 11 at 23:54 | answer | added | heap underrun | timeline score: 31 | |
| Oct 11 at 22:31 | comment | added | PattuX | @ThomasL pure arithmetic | |
| Oct 11 at 10:32 | comment | added | ThomasL | Is there a mapping to something different then numbers, f.e. letters or similar. Or is it pure number arithmetic? | |
| Oct 11 at 9:12 | comment | added | PattuX | @dvx2718 I added the examples, and added leading zeros as a hint (similar to base, I also did not consider that initially, but together with Hint #13 it should be clear why this makes a difference). For your second comment: If you were to write it as a mathematical function, it would not be conditional. However you'd probably want to define a an auxiliary variable first, and use that to define the final result. For a programming function, in my Python implementation I used one for-loop + one if-else-block (tho I'm not sure how much this helps, as you can probably code it 20 different ways) | |
| Oct 11 at 8:54 | history | edited | PattuX | CC BY-SA 4.0 |
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| Oct 11 at 2:14 | comment | added | dvx2718 | @PattuX Sorry just one more question. You said you could code this into a function but it's better to understand it as a series of steps. If you do put this as a function, then would it be conditional? (Aka one definition for x>0 and another for x<=0) In other words, if you are to code this with a programming language, will it use the IF statement? If so, how many ramifications? (Just 2, if...else..., or 3, if...else if...else... or even 4/more, if...else if...else if...else?) | |
| Oct 11 at 2:06 | comment | added | dvx2718 | @PattuX Two questions. 1. Do leading zeros matter? Aka is 3#5 = 03#0005 (all base 10)? 2. Can you give 1#234, 12#34, and 123#4? Thanks! | |
| Oct 10 at 22:19 | comment | added | PattuX | @ThomasL done :) | |
| Oct 10 at 22:19 | history | edited | PattuX | CC BY-SA 4.0 |
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| Oct 10 at 21:13 | comment | added | ThomasL | Can you please provide the results for 4#1 and 100#1 | |
| Oct 4 at 8:52 | comment | added | PattuX | @ConnieMnemonic at first, maybe a week given enough examples because I thought if I had this idea while solving another puzzle, surely someone else will have had a similar idea. Well, I learned this is not the case... :D However, now with Hint #17 and #18 giving the direction of the idea I think this is solvable. | |
| Oct 3 at 22:03 | comment | added | ConnieMnemonic | Real talk @PattuX - when you made this puzzle did you expect people to take this long with it? :P | |
| Oct 3 at 21:30 | history | edited | PattuX | CC BY-SA 4.0 |
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| Oct 3 at 21:30 | comment | added | PattuX | @ThomasL no, I added a counterexample | |
| Oct 3 at 8:37 | comment | added | Marius | @EtackSxchange. No, of course not. they are pretty close, but not exact. it was meant as a stupid math joke. | |
| Oct 2 at 18:20 | comment | added | ThomasL | I see a#0=10 for a=1,2,3,4,5. Is this true for all positive integers a? | |
| Oct 2 at 18:15 | comment | added | Fabio says Reinstate Monica | @EtackSxchange That comment ends with "note, this should not be taken seriously". | |
| Oct 2 at 17:33 | comment | added | Etack Sxchange | @Marius Are the numbers in your quadratic equation accurate? | |
| Oct 2 at 15:38 | history | edited | PattuX | CC BY-SA 4.0 |
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| Oct 2 at 15:24 | comment | added | PattuX | @ThomasL no, it is not | |
| Oct 2 at 15:24 | comment | added | PattuX | @not my real name yes, indeed it is the former | |
| Sep 28 at 19:44 | comment | added | ThomasL | Is the edge case in Hint19 the definition of $0^0=1$ ? | |
| Sep 22 at 16:15 | comment | added | Junelilly | I suspect due to Hint 18 the rot13(pbawrpgher) from Hint 12 is either rot13(gur Gjva Cevzr Pbawrpgher be Tbyqonpu'f pbawrpgher) | |
| Sep 19 at 9:58 | comment | added | PattuX | Added a hint. Again loops back to the 'different bases' question and I'm still not sure whether this helps or just adds more confusion ^^ | |
| Sep 19 at 9:53 | history | edited | PattuX | CC BY-SA 4.0 |
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| Sep 1 at 20:14 | comment | added | ThomasL | Is it possible to get 0 or 1 as a result? If yes, can you please provide an example for this. | |
| May 30 at 8:24 | comment | added | Fabio says Reinstate Monica | @Someone An example of why the base is relevant: uvag #11 gryyf hf gung S#S naq 15#15 ner qvssrerag, gubhtu gurl ner gur fnzr ahzore (S va urk = 15 va qrp). Vs gur erfhygf ner qvssrerag vg zhfg or orpnhfr gurer vf fbzr "aba-zngurzngvpny" bcrengvba, naq cre #13 jr xabj gur bcrengbe hfrf pbapngrangvba. Pbapngrangvba jbhyq tvir SS = 255 va bar pnfr, ohg 1515 va gur bgure. Gur ernfba vf gung SS genafyngrf gb 15k16 + 15, juvyr 1515 orpbzrf 15k100 + 15, naq gur qvssrerapr (zhygvcylvat ol 16 be 100) pbzrf sebz gur qvssrerag onfrf. | |
| May 29 at 19:29 | comment | added | Someone | But then what do the bases of the numbers have to do with anything? | |
| May 28 at 10:57 | comment | added | ConnieMnemonic | @azi I don't agree that rot13(uvag 18 ersref gb n "crnx" bcrengbe yvxr *. V zber fhfcrpg vg unf fbzrguvat gb qb jvgu cevzr snpgbef. "Gur bcrengbe vf va gur orfg sbez bs vg'f yvsr". Guvf vf zber pbzzbayl fgngrq nf "cevzr bs vg'f yvsr". Naq gura "fvmr vf gur bayl snpgbe". Cevzr + snpgbe.) | |
| May 27 at 18:54 | comment | added | azi | I think that the operator rot13(pbzovarf inevbhf zrnavatf bs gur punenpgre ^. Uvagf 17 naq 18 fhttrfg guvf punenpgre: gur cuenfr "...fzhqtr :/" va uvag 17 pna or vagrecergrq nf gur fzhqtr jvcvat bhg gur evtug unys bs gur ^ flzoby, juvyr uvag 18 vf nyyhqvat gb fbzrguvat yvxr na ncrk/cevzr cerqngbe - n crnx bcrengbe, juvpu ^ vaqrrq erfrzoyrf. Vg nyfb pbaarpgf jvgu gur "pbapngrangvba" uvag: gur flzoby ^ ercerfragf "NAQ" va ybtvp. Vg pbhyq nyfb vzcyl rkcbaragvngvba vf vaibyirq nf jryy.) | |
| May 20 at 19:46 | comment | added | Dr Xorile | I wouldn't hold your breath waiting for me! | |
| May 16 at 21:14 | history | edited | PattuX | CC BY-SA 4.0 |
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| May 16 at 21:13 | comment | added | PattuX | A chatroom might be a good option. I'm not so sure about the movie - after all it's still just a math puzzle and not an artistic masterpiece ;) I already fear people being disappointed as they expect the most elegant solution such a puzzle has ever had after such a long time. On that note - maybe Dr Xorile is close as both assertions are correct! | |
| May 16 at 16:56 | comment | added | Dr Xorile | Is 1#0=10? And is 5#0=10? | |
| May 11 at 16:37 | comment | added | Someone | One could make a movie out of this. | |
| May 11 at 14:40 | comment | added | ConnieMnemonic | At this point we should open a chatroom, a conference and a series of half-hour YouTube documentaries. | |
| May 10 at 13:02 | comment | added | Sny | Should we open a chatroom? @PattuX | |
| May 8 at 2:37 | comment | added | ApexPolenta | @suchislife Everyone has to start somewhere. If you think you know the answer, go for it | |
| May 8 at 2:25 | comment | added | suchislife | Since I am new to puzzling.stackexcahnge.com, is it appropriate to try and answer this question? I see you are having a lot of fun posting hints going on 10 months! =) | |
| S May 7 at 16:06 | history | bounty ended | CommunityBot | ||
| S May 7 at 16:06 | history | notice removed | CommunityBot | ||
| May 6 at 14:01 | history | edited | PattuX | CC BY-SA 4.0 |
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| May 6 at 13:58 | comment | added | PattuX | I will already tell you that the brute-force approach will not work. The "magic constant" I was referring to is the base of the input (Hint 11 was supposed to clarify that). While I like the idea of the Devil's calculator, I don't know how to and you seem to need a premium account there... In any case, I added another hint | |
| May 5 at 22:25 | comment | added | ApexPolenta | @ConnieMnemonic Maybe try digit rotation? For example, 1234 rotates to either 2341 or 4123. I have a feeling that's what "smudge" means in hint 17. | |
| May 5 at 15:02 | comment | added | Someone | Perhaps the emoticon in hint 17 is a reference to base64 or something? | |
| May 5 at 8:57 | comment | added | ConnieMnemonic | Also, my suspicion is that one of the operations is Pow. One of the hints suggests a constant for the mathematically inclined, and my guess is OP is referring to X^0=1. | |
| May 5 at 8:54 | comment | added | ConnieMnemonic | So far I have add, sub, mul, div, mod, pow and concat. | |
| May 5 at 8:53 | comment | added | ConnieMnemonic | @Solvers I've built a little console app that can crunch through all permutations of arbitrary operations. Put suggestions for new ones below and I'll implement them to the engine. Maybe we can bruteforce this. | |
| May 4 at 23:00 | comment | added | Benjamin Wang | Indeed, if there were 3-4 steps, then even if you submit it to Devil's Calculator where players can try unlimited attempts, it will be a challenge. | |
| May 4 at 21:50 | comment | added | Fluorine | 4 steps? No wonder it's a long standing puzzle, I think elegance in number sequence or similar black box functions comes from the a pattern despite being hard to spot is a straightforward process. Many steps will make the answer feel a bit random I fear. | |
| May 4 at 9:22 | comment | added | PattuX | (1) Yes, both numbers have to be in the same positional base (2) Depends on what you consider a step, but I'd say 3, maybe 4. One of them involves comparisons. (3) Hint 17 is an actual clue | |
| May 3 at 15:55 | comment | added | ᵍʰᗣˢᵗ | I can't tell if clue 17 is a real clue or something that actually happened. I assume it's a clue? | |
| May 3 at 13:40 | comment | added | ConnieMnemonic | How many steps in the entire process? And are there any steps that involve comparison? | |
| May 3 at 13:32 | comment | added | Someone | Are both numbers necessarily in the same positional base? | |
| May 3 at 9:18 | comment | added | PattuX |
Oh, good observation. This is the only expecting tho. If a or b are non-zero, hint 16 is true
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| May 3 at 2:44 | comment | added | Bubbler |
0#0=2 seemingly contradicts hint 16. Is it wrong, or is it an exception?
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| May 3 at 0:33 | comment | added | PattuX | Yes and yes. Also another hint. | |
| May 3 at 0:32 | history | edited | PattuX | CC BY-SA 4.0 |
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| May 2 at 15:54 | comment | added | Fluorine | @PattuX (1) can a sixth grader understand that conjecture and (2) can you give 41#43 and 43#41? | |
| Apr 30 at 14:17 | comment | added | PattuX | Answering the three questions above: (1) The math is accessible to everyone, I'd say it's 6th grade math or so (2) The conjecture is very well known within mathematics. (3) I'm not too familiar with non-integer bases, but I don't think they work | |
| Apr 30 at 12:22 | comment | added | Sny | @PattuX will non-integer bases work? | |
| Apr 30 at 12:12 | comment | added | Sny | @PattuX You say that "... if a certain conjecture holds". How well known is the conjecture? | |
| Apr 30 at 6:35 | comment | added | PDT | @PattuX is the math behind this accessible to everyone? | |
| Apr 29 at 15:16 | comment | added | PattuX | I completely forgot about this thread and only got reminded because of the bounty. I added the requested examples and also another small hint (more of a confirmation I guess). Also to get rid of the tedious spoilering, I added all hints that were just additional examples to the list of given results. | |
| Apr 29 at 15:09 | history | edited | PattuX | CC BY-SA 4.0 |
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| S Apr 29 at 13:17 | history | bounty started | Jafe | ||
| S Apr 29 at 13:17 | history | notice added | Jafe | Draw attention | |
| Nov 26, 2023 at 19:44 | comment | added | ChimiSeanGa | Can you provide the result for 52#3 and 53#1? | |
| Sep 29, 2023 at 10:22 | review | Suggested edits | |||
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| Aug 31, 2023 at 19:15 | comment | added | Benjamin Wang | Can you submit your function to The Devil's Calculator so that we can try it interactively? | |
| Jul 14, 2023 at 13:38 | history | edited | PattuX | CC BY-SA 4.0 |
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| Jul 14, 2023 at 13:35 | comment | added | PattuX | @codewarrior0 Yes, the base can be seen as a third input. At first I implicitly used base 10 and did not think about other bases. Sorry about the confusion. | |
| Jul 13, 2023 at 21:51 | comment | added | ThomasL | Can you provide the result for 0#0 ? | |
| Jul 4, 2023 at 20:51 | comment | added | codewarrior0 | The operands can't be in any base at all if the operands are natural numbers. The operands would have to be written numbers for the base to matter. Did you mean that the base is a third operand to the operator? | |
| Jul 4, 2023 at 19:53 | comment | added | 1357924680a | I think that'll help: rot5(75, 77, 751, 88, 94, 00, 066, 062, 169, 467, 461, 658). | |
| Jul 4, 2023 at 19:49 | comment | added | 1357924680a | Concanetation? This would be a big clue! | |
| Jul 4, 2023 at 17:50 | history | edited | PattuX | CC BY-SA 4.0 |
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| Jun 27, 2023 at 15:15 | comment | added | ConnieMnemonic | My brain might be about to authentically melt out of my ears. | |
| Jun 27, 2023 at 14:04 | comment | added | PattuX | Added two more hints. Originally I did not mean for the input to be in other bases but it extends pretty naturally and I think it may actually help quite a bit in figuring it out. | |
| Jun 26, 2023 at 23:42 | history | edited | PattuX | CC BY-SA 4.0 |
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| Jun 26, 2023 at 14:39 | comment | added | ConnieMnemonic | I haven't made any good progress. For what it's worth, my suspicion is also that the implied constant is rot13(gur enqvk/onfr bs gur ahzore flfgrz, juvpu nccrnef gb or onfr 10. guvf pbhyq or zvfyrnqvat gubhtu.) On that note, OP, here's a hint request; can you do 0xF#0xF for us? Possibly 0x2#0x2 also? | |
| Jun 26, 2023 at 14:37 | comment | added | dvx2718 | @ChrisLewis I was thinking that the "implicit constant"could be rot13(ybtnevguz, nf ybt jbhyq or vzcyvpvgyl onfr-10, be ya jbhyq or vzcyvpvgyl onfr-r, gubfr ner uvqqra pbafgnagf) | |
| Jun 26, 2023 at 13:19 | comment | added | Chris Lewis | Anyone getting anywhere on this? I wonder if hint #10 is perhaps about a rot13(Svobanppv frdhrapr naq gur tbyqra engvb). It might be nice to get some values for a fixed a or b, maybe even 1#b and a#1 for a few cases. | |
| Jun 23, 2023 at 10:17 | comment | added | tehtmi | Related to theozh's observation, rot13(o vf qvivfvoyr ol svir vss gur erfhyg vf nyfb (cerivbhf bofreingvba, gur fnzr vf gehr sbe gjb)) | |
| Jun 23, 2023 at 9:34 | history | edited | PattuX | CC BY-SA 4.0 |
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| Jun 23, 2023 at 6:25 | comment | added | franck vivien | I'd like to see a counter-example of "0#b is a prime". Or to get value of 0#5 and 0#8... | |
| Jun 22, 2023 at 20:36 | comment | added | dvx2718 | I deduce that 5#23=11... Can I get the value for 5#23 and 5#31? | |
| Jun 22, 2023 at 13:08 | comment | added | ConnieMnemonic | New hints are really useful. I might take a proper programmatic crack at this tonight. I'm curious if you can reveal this in a hint, but I wanted to know; does the underlying algorithm involve any hidden coefficients/constants? Say, "divide b by 3"? Or are the only two values at play "a" and "b", transforming one another? | |
| Jun 22, 2023 at 10:52 | history | edited | PattuX | CC BY-SA 4.0 |
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| Jun 21, 2023 at 13:27 | comment | added | theozh | the only striking thing for me (so far) is rot13(vs o vf bqq (be rira) gur erfhyg vf nf jryy.). But maybe there will be counter examples in the future? | |
| Jun 21, 2023 at 11:52 | history | edited | PattuX | CC BY-SA 4.0 |
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| Jun 21, 2023 at 10:22 | comment | added | PattuX | I've added Dr Xorile's questions for now and will add the others later or tomorrow. | |
| Jun 21, 2023 at 10:20 | history | edited | PattuX | CC BY-SA 4.0 |
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| Jun 21, 2023 at 10:12 | comment | added | ConnieMnemonic | @Marius Could be. I'm just curious because 2#2 = 2, 3#3 = 3, 5#5 = 5, but suddenly 13#13 = 19? I'm wondering if there's some wacky modulo stuff happening. | |
| Jun 21, 2023 at 8:48 | comment | added | Prim3numbah | I feel like I see a pattern of primes but not sure. Is a#a always a prime? | |
| Jun 21, 2023 at 8:44 | comment | added | Marius |
@ConnieMnemonic my bet is on 1000#1000 = 1000, but I could be wrong
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| Jun 21, 2023 at 8:41 | comment | added | ConnieMnemonic | Any chance we can see something wacky, like 1000#1000? | |
| Jun 20, 2023 at 21:58 | comment | added | Dr Xorile | Is $a\#b$ valid for all integers $a$ and $b$? | |
| Jun 20, 2023 at 21:50 | comment | added | Dr Xorile | What happens if $a=0$? | |
| Jun 20, 2023 at 19:33 | history | edited | PattuX | CC BY-SA 4.0 |
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| Jun 20, 2023 at 14:53 | comment | added | ConnieMnemonic | Could we see another number # by 0? Say, 3#0? | |
| Jun 19, 2023 at 9:24 | comment | added | PattuX | Added some hints. @Marius Actually I would have been quite impressed to see the 12 data points happen to fit on a quadratic ;) | |
| Jun 19, 2023 at 9:21 | history | edited | PattuX | CC BY-SA 4.0 |
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| Jun 19, 2023 at 8:49 | comment | added | Marius |
the # is the function f(x, y) = -0.2679x² + 0.0536y² + 0.6429x - 0.4286y + 11.2857 and the value of 3#19 is approximately 2.7. (note, this should not be taken seriously)
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| Jun 19, 2023 at 7:04 | comment | added | quarague | This would be a hint, so your call when or whether to tell us: Is it always true that a#b=b#a? | |
| Jun 18, 2023 at 14:56 | comment | added | Chipster | I have the same questions as Someone, but also ROT13(Vf vg pbzzhgngvir? Va bgure jbeqf, qbrf n # o rdhny o # n) | |
| Jun 18, 2023 at 14:34 | comment | added | Someone | It feels like rot13(rkcbaragf ner vaibyirq). Also, is it always true that rot13(ehaavat gur bcrengvba jvgu gur fnzr k ba obgu fvqrf ergheaf k)? | |
| Jun 18, 2023 at 14:05 | history | asked | PattuX | CC BY-SA 4.0 |