Logo

Greetings from The On-Line Encyclopedia of Integer Sequences!

Hints

Search: id:A143477
Displaying 1-1 of 1 results found. page 1
     Format: long | short | internal | text      Sort: relevance | references | number      Highlight: on | off
A143477 Kolakoski Fan. +0
6
1, 2, 2, 2, 1, 1, 2, 2, 1, 2, 1, 1, 2, 2, 2, 1, 1, 2, 1, 2, 2, 1, 1, 1, 1, 2, 1, 2, 2, 1, 2, 2, 1, 1, 2, 1, 2, 1, 2, 2, 1, 2, 2, 1, 1, 2, 1, 1, 2, 2, 1, 2, 1, 1, 2, 2, 2, 1, 2, 2, 1, 1, 2, 1, 1, 2, 2, 1, 2, 1, 1, 2, 1, 2, 2, 1, 1, 2, 1, 1, 2, 1, 2, 2, 1, 1, 2, 2, 1, 2, 2, 1, 1, 2, 1, 2, 2, 1, 2, 1, 1, 2, 2, 1, 2 (list; table; graph; listen)
OFFSET

1,2

COMMENT

(1) Does every row occur infinitely many times as a segment of A000002?

(2) In Kolakoski's note, the initial 1 appears at the bottom, centered,

with 2 just above and successive rows arise as branches so that the

array resembles a handheld fan.

Arises from the Kolakoski sequence, K(n)=A000002(n), as follows:

row 1: 1

row 2: 2

row 3: 2 2

row 4: 1 1 2 2

row 5: 1 2 1 1 2 2,

and so on, where the first term in row n is K(n) and row n-1 tells how many of each kind (1 or 2) to write in row n.

REFERENCES

William G. Kolakoski, unpublished note entitled "Kolakoski Series Fan," dated Nov 12, 1993.

LINKS

Wikipedia, Kolakoski sequence

EXAMPLE

Row 4 (1,1,2,2) determines row 5: (one 1, one 2, two 1's, two 2's).

CROSSREFS

Cf. A000002.

Sequence in context: A062246 A037811 A091237 this_sequence A134143 A085684 A141604

Adjacent sequences: A143474 A143475 A143476 this_sequence A143478 A143479 A143480

KEYWORD

nonn,tabl

AUTHOR

Clark Kimberling (ck6(AT)evansville.edu), Aug 19 2008, Aug 25 2008

page 1

Search completed in 0.002 seconds

Lookup | Welcome | Find friends | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Transforms | Puzzles | Hot | Classics
More pages | Superseeker | Maintained by N. J. A. Sloane (njas@research.att.com)

Last modified December 20 16:54 EST 2009. Contains 171081 sequences.


AT&T Labs Research