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A085297 Nonzero residues of Catalan sequence modulo 3; related to the Thue-Morse sequence (A001285). 1
1, 1, 2, 2, 2, 2, 2, 2, 1, 1, 1, 2, 2, 2, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 1, 1, 1, 1, 1, 1, 2, 2, 2, 1, 1, 1, 2, 2, 2, 2, 2, 2, 1, 1, 1, 2, 2, 2, 1, 1, 1, 1, 1, 1, 2, 2, 2, 1, 1, 1, 2, 2, 2, 2, 2, 2, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 1, 1, 1, 2, 2, 2, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 1, 1, 1, 1, 1, 1, 2 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

COMMENTS

The runs of zeros in between the digit strings are given in A085296.

LINKS

Table of n, a(n) for n=1..105.

FORMULA

If a leading '1' is added to the Catalan sequence modulo 3, the only nonzero digit strings are {1, 1, 1, 2, 2, 2} and {2, 2, 2, 1, 1, 1}. Replacing these digit strings with their first digit, {1, 1, 1, 2, 2, 2} -> '1' and {2, 2, 2, 1, 1, 1} -> '2', then omitting all zeros, results in the Thue-Morse sequence.

CROSSREFS

Cf. A001285 (Thue-Morse), A000108 (Catalan), A039969 (d-perfect), A085296.

Sequence in context: A027354 A192227 A102673 * A080972 A037814 A179529

Adjacent sequences:  A085294 A085295 A085296 * A085298 A085299 A085300

KEYWORD

nonn

AUTHOR

Paul D. Hanna, Jun 24 2003

STATUS

approved

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Last modified June 20 17:27 EDT 2019. Contains 324234 sequences. (Running on oeis4.)