[seqfan] Re: An integer-cellular automata (in French)

[Eric Angelini]

Hello SeqFans,
Page has been updated with two nice contributions by
Douglas McNeil and Maximilian Hasler:

http://www.cetteadressecomportecinquantesignes.com/AutomateNBR01.htm

We have 'gliders' -- and a (possibly) interesting integer 987!
Best,
É.
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(translation in very short):
- start generation zero with an integer, put somewhere on a single
  line of squares, one digit per square
- now (generation n+1) all digits start to move simultaneously:
  * an odd digit k moves k squares to the the left -- then is
    turned into k+1
  * an even digit j moves j squares to the the right -- then is
    turned into j+1
- a single square shows at generation n+1 the sum of the digits
  that land there -- but:
  * if a single square has to host a quantity > 9, than the 
    "special addition/carry" rule applies:

    Say that the cumulative effect of generation n produces at
    the next generation (n+1) a local situation where square
    'a' is 31, square 'b' is 28, 'c' is 5 and 'd' is empty:
 
    We have thus [generation n+1] : ....abcd....
    
    Now:
    1) write on three parallel lines the 'influence' of each
       integer a, b and c
    2) give two squares to a 2-digit integer a, b or c -else only
       one- aligned on the letter's position
 
    According to (1) et (2), the 'influences' of a, b, c and d
    give:

    generation n+1 : ....abcd....
    image of 'a' :   ....31......
    image of 'b' :   .....28.....
    image of 'c' :   ......5.....
 
    Proceed to "special addition/carry" (from left to right):

    generation n+1 : ....abcd....
    image of 'a' :   ....31......
    image of 'b' :   .....28.....
    image of 'c' :   ......5.....
                     ------------
    SPECIAL ADDn :   ....3313....
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