[seqfan] RE : Look and Say novelty?

[Eric Angelini]

sorry, start with 22, 3233, etc.


-------- Message d'origine--------
De: seqfan-bounces at list.seqfan.eu de la part de Eric Angelini
Date: mer. 28/01/2009 19:25
À: Sequence Fanatics Discussion list
Objet : [seqfan]  Look and Say novelty?
 

Hello SeqFans,

I like this finite one -- which kind of self-constructs nicely:

S = 1, 213223, 31424344, 
               4152535455,
               516263646566, 
               61727374757677,
               7182838485868788,
               819293949596979899.

... a(n) says: "Look, we have so far in the sequence (including my
digits), this quantity of digits 'a', that quantity of digits 'b',
etc."

Example: a(2) says "there are two 1's so far (including my digits)"
                       -> yes, the '1' of a(1) and the '1' of a(2); 
                   "there are three 2's so far"
                       -> yes, my three 2's;
                   "there are two 3's so far"
                       -> yes, my two 3's.

         a(3) says "there are three 1's, four 2's, four 3's, four 4's
                    so far (including my digits)"
                       -> yes, ...

Are there other such sequences, with different start for instance?

And if this sequence is submitted, does a(2) have to be written 212332?

Best,
É.


                       

                        


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