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-   -   My favourite number sequence. (https://www.askmehelpdesk.com/showthread.php?t=64183)

  • Feb 19, 2007, 08:05 AM
    Capuchin
    My favourite number sequence.
    Here is an interesting number sequence.

    It is available on the web so please take it in the spirit it is given, for good fun, and don't look it up.

    Here are the first 10 terms:

    0, 0, 0, 0, 4, 9, 5, 1, 1, 0,

    I ask you to post the next unconfirmed number in the sequence, without explaining why, so that others may have a go.

    I will reveal extra numbers if nobody gets the next term in a day or so.
    I will also let people know if their term is correct.
    On Friday I will give the rule for anybody who is still stuck.

    Many thanks for observing these guidelines to maximise everyone's fun :)

    Feel free to post thoughts and suspicions though :) - clues will be available if nobody is on the right track
  • Feb 19, 2007, 09:19 AM
    asterisk_man
    I'm guessing that the sequence is based on an external data source. i.e. it is not a mathematical function like f(n). Looking at f(n)-f(n-1) and f(n)/f(n-1) reveal no obvious patterns. I'll continue to investigate!
  • Feb 19, 2007, 09:37 AM
    colbtech
    Are these the last 10 scores made by English opening batsmen in cricket?
  • Feb 19, 2007, 09:45 AM
    Capuchin
    Entertaining guess colbtech

    Not right though :)

    I don't think I'll comment on mathematical function yet asterisk.
  • Feb 19, 2007, 10:51 AM
    asterisk_man
    So hard to investigate something without using Google! :)
    Can't be a simple letter/number substitution. No word starts with 4 consecutive same letters. The answer is available on the web so it must not be using any of the sentences that capuchin wrote that would only apply to this forum at this time as a data source.
    Since I have nothing better I will make the naïve guess that it is a simple repeating pattern
    0, 0, 0, 0, 4, 9, 5, 1, 1,0, 0, 0, 0, 4, 9, 5, 1, 1, 0, 0, 0, 0, 4, 9, 5, 1, 1, 0,
    So the next number would be 0? Maybe capuchin will let a hint fly when he tells me I'm wrong :)
  • Feb 19, 2007, 10:57 AM
    Capuchin
    Well that wouldn't be very exciting would it :p

    I'm going to wait till tomorrow to give a clue.
  • Feb 19, 2007, 11:07 AM
    asterisk_man
    So 0 is or is not the next term in the sequence :)
  • Feb 19, 2007, 11:10 AM
    Capuchin
    Is not.
  • Feb 19, 2007, 11:27 AM
    asterisk_man
    Maybe letter count in some text? But what text would have zero a b c d j and 3*e 9*f 5*g 1*h 1*i ? That's a lot of f for so few e. e should be about 12.7% of the letters so the text would be about 24 characters long but f should only be 2.2% so the text would be about 409 characters long. Based on this inconsistency I'm guessing it isn't letter count or the text is short, about 30 characters and has unusual words.
    Just thinking aloud so feel free to tell me your side... if anyone else is working this besides me.
  • Feb 19, 2007, 11:32 AM
    Capuchin
    Okay, a mini clue, it's an infinite sequence.

    I don't want to give too much away until the other math heads have popped in
  • Feb 19, 2007, 11:35 AM
    asterisk_man
    OK. Everyone else must be asleep. I'll try to sit on this one until I find an answer or tomorrow comes around :)
  • Feb 19, 2007, 01:04 PM
    galactus
    I only know (I think) because I have seen this before. Is the next number 55?
  • Feb 19, 2007, 01:26 PM
    Capuchin
    Hehe yes galactus,

    Anyone want to guess the 12th term? :)

    (I think that should confuse asterisk man)
  • Feb 20, 2007, 07:57 AM
    asterisk_man
    Agreed! Very confused!
  • Feb 21, 2007, 01:23 AM
    Capuchin
    0, 0, 0, 0, 4, 9, 5, 1, 1, 0, 55,.

    Anyone want to hazard a guess at term 12? :)
  • Feb 21, 2007, 07:43 AM
    asterisk_man
    I want to hazard a guess but I can't because I can't figure out a pattern! And the "I think that should confuse asterisk man" comment confuses me most of all :)
  • Feb 21, 2007, 07:46 AM
    Capuchin
    I was simply commenting that it going from a nice single digit sequence up to 55 would confuse anybody, especially you as you are putting some effort into it :p
  • Feb 21, 2007, 07:47 AM
    galactus
    The 12th term is 55 also. The 13th is 1.
  • Feb 21, 2007, 07:48 AM
    Capuchin
    *shakes fist at galactus*

    You've given it away now! :P
  • Feb 21, 2007, 07:50 AM
    galactus
    I doubt it. The pattern is rather obscure for anyone to find. The only reason I know it is because I seen it several years back. I will stay out of it from here on out. We'll see if anyine gets it. Some bright folks here.
  • Feb 21, 2007, 07:54 AM
    Capuchin
    Hehe someone will get it, I was being a little sarcastic with the given it away comment :p

    I know someone at my place of work who got it (took them half a day though)
  • Feb 21, 2007, 07:55 AM
    galactus
    No worries. I'm not thin-skinned

    So there:p :D
  • Feb 21, 2007, 08:19 AM
    asterisk_man
    *dim bulb*
  • Feb 21, 2007, 09:49 AM
    Evil dead
    0, 0, 0, 0, 4, 9, 5, 1, 1, 0, 55, 55, 1.

    Hmm. This is something to do with square root or cube root. The way it shoots up to 55 then straight back down to 1 is quite bemusing.

    How ever, what I do know that it is based on Computer Science or some sort of Binary Code.
  • Feb 21, 2007, 09:55 AM
    Capuchin
    Hi Evil dead and welcome to the discussion!

    Maybe you and asterisk man can shove your heads together! :)
  • Feb 21, 2007, 10:55 AM
    asterisk_man
    Based on the initial 4 zeros I'm led to believe that the function is f(n-1,n-2,n-3,n-4) and that terms 1 2 3 4 are the initial conditions.
  • Feb 21, 2007, 10:56 AM
    Capuchin
    You would be incorrect in that belief.
  • Feb 21, 2007, 12:57 PM
    asterisk_man
    is it a sequence which is defined by the numbers that capuchin and galactus randomly generate for the purpose of keeping asterisk_man in a perpetual state of confusion?? If that's the case, is the next term in the sequence ?
  • Feb 21, 2007, 01:02 PM
    Capuchin
    Eheehehehhehe

    Okay here is a huge clue.

    The terms that you might want to concentrate on are five, six, eleven and twelve.
  • Feb 22, 2007, 01:52 AM
    colbtech
    Well I can't remember the last time an England opener scored 55 ? Cou;dn't you have started with a sequence like 1,2,3,4,5,

    Think I could have coped with that one. (Hint: Nothing to do with cricket!)
  • Feb 22, 2007, 07:55 AM
    Capuchin
    Another clue?

    The sequence is poorly defined beyond term 34
  • Feb 24, 2007, 02:44 PM
    galactus
    Cap, ol' buddy, it's time you gave it up. Think mapping and Roman numerals.
  • Feb 24, 2007, 02:52 PM
    Capuchin
    Yes I completely forgot about this lol

    The sequence is formed by taking each term, removing all letters that aren't I, V, X, L, C, D, or M, and then reading the number as a roman numeral.

    for example, six = ix = 9
    twelve = lv = 55

    It's poorly defined after term 34 because thirty-five is iiv which is not a standard roman numeral.

    It is sequence A002904 in the The On-Line Encyclopedia of Integer Sequences.

    Thanks for playing.
  • Feb 24, 2007, 03:29 PM
    galactus
    The pattern is rather obscure.

    one=0
    two=0
    three=0
    four=0
    fIVe=4
    sIX=9
    seVen=5
    eIght=1
    nIne=1
    ten=0
    eLeVen=55
    tweLVe=55
    thIrteen=1
    fourteen=0
    fIfteen=1
    sIXteen=9
    seVenteen=5
    eIghteen=1
    nIneteen=1
    twenty=0
    twenty-0ne=0
    twenty-two=0
    twenty-three=0
    twenty-four=0
    twenty-fIVe=4
    twenty-sIX=9
    twenty-seVen=5
    twenty-eIght=1
    twenty-nIne=1
    thIrty=1
    .
    .
    .
    .
    .
    seVenty-sIX=59

    And so on and so on. See the pattern?
  • Feb 24, 2007, 05:11 PM
    Capuchin
    Why is vix 59? :/ it's poorly defined also. Could be 59, or 4, or 14, or 45. They would write 59 as lix
  • Feb 25, 2007, 02:34 AM
    agneau
    Quote:

    Originally Posted by Capuchin
    okay, a mini clue, it's an infinite sequence.

    This reminds me of this other sequence: 3, 3, 5, 4, 4, 3, 5, 5, 4, 3, 6, 6...

    (although that looks fairly regular... it is not about the numbers themselves but about the number of letters in the words ONE, TWO, THREE etc... )

    I am convinced they are similar somehow... but I am thrown by the 0, 0, 0... assuming it is something to do with the words ONE, TWO etc... could it be a formula e.g. relating the number of vowels to consonants? Or should I be looking at other languages than English?

    ONE, TWO, THREE all have
    abs(Vowels - Consonants) - 1 = 0
    but this fails with FOUR

    and it could never give an answer of 9!

    before I try to pursue this any further and totally go mad... am I on the right track?

    a
  • Feb 25, 2007, 03:51 AM
    Capuchin
    Erm, I've given the answer ;)
  • Feb 25, 2007, 06:42 AM
    agneau
    Quote:

    Originally Posted by Capuchin
    Erm, i've given the answer ;)

    LOL... I guess I should make sure I have read the whoe thread, not just the first page, before replying! At least that gave me something fun to think about for a bit. And I am relieved I wasn't being completely thick. That is the sort of sequence it is impossible to work out unless you have a BIG clue... like the answer!

    Thanks

    A
  • Feb 25, 2007, 07:48 AM
    Capuchin
    It's not that hard, you just need to tweak it.
  • Feb 26, 2007, 07:45 AM
    asterisk_man
    OK. I was starting to get in the right ballpark. I knew that it had something to do with the names of the numbers. Though I hadn't quite made the leap to roman numerals yet.

    Tricky sequence!

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