

A106004


First monotonically increasing sequence such that erasing the first and last digit of each term and concatenating what is left results in the concatenation of all terms of the sequence.


1



110, 111, 200, 210, 211, 212, 220, 300, 400, 420, 510, 600, 620, 710, 711, 720, 810, 820, 822, 823, 900, 930, 1000, 1400, 2040, 2200, 2510, 3060, 4000, 4620, 5070, 6100, 6710, 7170, 7200, 7810, 8080, 8200, 9280, 12390, 20090, 23010
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OFFSET

1,1


COMMENTS

Could one say this is kind of fractal?


LINKS

Table of n, a(n) for n=1..42.


EXAMPLE

To avoid numbers beginning with 0, we assume the first term is 1xy, and so x=1, so 11y, but y=0 works, so the first term is 110.
The next two terms must be a1b, c0d, and se we take a=b=1, c=2, d=0, so now the sequence begins 110, 111, 200. And so on.


CROSSREFS

Cf. A106003.
Sequence in context: A039724 A008944 A306701 * A113556 A286943 A285911
Adjacent sequences: A106001 A106002 A106003 * A106005 A106006 A106007


KEYWORD

base,easy,nonn


AUTHOR

Eric Angelini, Apr 29 2005


STATUS

approved



