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 A143477 Kolakoski Fan. 5
 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; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS (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in row n is K(n) and row n-1 tells how many of each kind (1 or 2) to write in row n. REFERENCES William G. Kolakoski, unpublished note entitled "Kolakoski Series Fan," dated Nov 12, 1993.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 * A214774 A320107 A190321 Adjacent sequences:  A143474 A143475 A143476 * A143478 A143479 A143480 KEYWORD nonn,tabl AUTHOR Clark Kimberling, Aug 19 2008, Aug 25 2008 STATUS approved

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Last modified January 18 04:47 EST 2019. Contains 319269 sequences. (Running on oeis4.)