[seqfan] Digits concatenation

Paolo Lava paoloplava at gmail.com
Thu Nov 10 09:31:58 CET 2011

Dear SeqFans,

I am thinking to a sequence where at any step “n” we concatenate all the
digits of all the natural numbers from 1 to n in order to build up two
numbers x and y that minimize the ratio x/y, being x/y integer (leading
zeros not admitted).

Starting with a(1)=1 we have a(2)=2 because 2/1=2, a(3)=4 because 12/3=4,
a(4)=33 because 132/4=33, a(5)=38 because 532/14=38, etc.

If we start from a(0)=0 we have a(1)=0 (0/1), a(2)=5 (10/2), a(3)=34
(102/3), a(4)=3 (102/34), etc.

Is there anybody who is willing to compute additional terms?



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