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A105690
A simple "Fractal Jump Sequence" (FJS).
0
2, 1, 2, 1, 1, 2, 1, 2, 1, 1, 1, 2, 2, 1, 1, 1, 1, 2, 2, 2, 1, 1, 1, 1, 1, 1, 2, 1, 2, 2, 2, 2, 1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 2, 2, 1, 2, 2, 2, 1, 2, 1, 2, 1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 2, 1, 2, 2, 1, 1, 2, 2, 2, 2, 1, 2
OFFSET
2,1
COMMENTS
See A105397 for definition of Fractal Jump Sequence.
This is how to construct the sequence: start with 2 on rows a and b; put 2 empty spaces behind the 2 on row a; choose any two digits and put them on row b under the 2 empty spaces of row a; go back to row a and add the same two digits but each one with its according spaces (1 must always be followed by 1 space on row a and 2 must always be followed by 2 spaces); go back to row b and add under the next available spaces of a the digits necessary so to have the same succession of digits in rows b and a. The sequence builds itself automatically. The row (c) is obtained by "pushing" (a) into (b) -- [the first digit of a and b melt in a single copy of themselves]. Row (c) is the FJS sequence above.
(a)..2..1.2..1.1.2..1.2..1.1.1.2..2.....
(b)..212.1.12.1.2.11.1.22.1.1.1.12.22...
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(c)..21211212111221111222111111212222...
EXAMPLE
To build such sequences one has only to choose the first digit d and the d digits to put under the d spaces of row (a).
CROSSREFS
Sequence in context: A347552 A300983 A279205 * A214364 A175922 A214856
KEYWORD
base,easy,nonn
AUTHOR
Eric Angelini, May 04 2005
STATUS
approved