A105690 A simple "Fractal Jump Sequence" (FJS).

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

Author

Eric Angelini, May 04 2005

Keywords

• base
• easy
• nonn

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...

Examples

			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).