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Nice brain teaser

  1. Feb 11, 2009 #1
    1,8,15,22,29,36,...............

    49,343,2401,.............

    77,74,71,68,65,.............

    What do all these sequences have in common?
     
  2. jcsd
  3. Feb 11, 2009 #2
    The digit 1
    :smile:
     
  4. Feb 11, 2009 #3

    DaveC426913

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    Well, they're all simple sequences...

    n=(n-1)+7
    n=(n-1)x7
    n=(n-1)-3
     
  5. Feb 12, 2009 #4
    - All of the numbers in the sequences are integers.
    - If you concatenate the digits of the sequences, each one has the digits "201".
    - Each sequence's odd-numbered entries are odd.
    - If you concatenate the digits of each sequence, and add the 25th through 35th digits, you'll get the same total, 42.

    DaveE
     
  6. Feb 13, 2009 #5

    neu

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    The number 7?
     
  7. Feb 13, 2009 #6

    DaveC426913

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    sigh.

    Commas, ellipses and integers.

    Asked & answered.

    math_04: we've given answers that have met the criteria. Either grant us a win or tell us there's a better answer than the ones we've provided.
     
  8. Feb 14, 2009 #7
    I guess its the number seven and the digits being integers. Am I getting the right answer to the teasers?





    ------------------
    tease your eyes
     
  9. Feb 14, 2009 #8

    DaveC426913

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    I don't see what 7 has to do with the third sequence.
     
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