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A036577
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Ternary Thue-Morse sequence: closed under a->abc, b->ac, c->b.
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7
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2, 1, 0, 2, 0, 1, 2, 1, 0, 1, 2, 0, 2, 1, 0, 2, 0, 1, 2, 0, 2, 1, 0, 1, 2, 1, 0, 2, 0, 1, 2, 1, 0, 1, 2, 0, 2, 1, 0, 1, 2, 1, 0, 2, 0, 1, 2, 0, 2, 1, 0, 2, 0, 1, 2, 1, 0, 1, 2, 0, 2, 1, 0, 2, 0, 1, 2, 0, 2, 1, 0, 1, 2, 1, 0, 2, 0, 1, 2, 0, 2, 1, 0, 2, 0, 1, 2, 1, 0, 1, 2, 0, 2, 1, 0, 1, 2, 1, 0, 2, 0, 1, 2, 1, 0
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,1
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COMMENTS
| Number of 1's between successive 0's in A010060.
The infinite sequence is abcacbabcbac... which is encoded with a->2, b->1, c->0 to produce this integer sequence.
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REFERENCES
| J. Grytczuk, Thue type problems for graphs, points and numbers, Discrete Math., 308 (2008), 4419-4429.
M. Lothaire, Combinatorics on Words. Addison-Wesley, Reading, MA, 1983, p. 26.
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LINKS
| J.-P. Allouche and J. O. Shallit, The Ubiquitous Prouhet-Thue-Morse Sequence, in C. Ding. T. Helleseth and H. Niederreiter, eds., Sequences and Their Applications: Proceedings of SETA '98, Springer-Verlag, 1999, pp. 1-16.
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FORMULA
| a(n) = A036585(n) - 1 = A029883(n) + 1.
a(n) = 3 - A007413(n). a(A036554(n)) = 1; a(A091785(n)) = 0; a(A091855(n)) = 2. - DELEHAM Philippe, Mar 20 2004
a(4*n + 2) = 1. a(2*n + 1) = 2 * A010059(n). a(4*n + 3) = 2 * A010060(n). - Michael Somos, Aug 03 2011
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EXAMPLE
| 2*x + x^2 + 2*x^4 + x^6 + 2*x^7 + x^8 + x^10 + 2*x^11 + 2*x^13 + x^14 + ...
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PROG
| (PARI) {a(n) = if( n<1, 0, if( valuation( n, 2)%2, 1, 1 - (-1)^subst( Pol( binary(n)), x, 1)))} /* Michael Somos, Aug 03 2011 */
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CROSSREFS
| Cf. A010059, A010060, A029883, A036585, A104248.
Sequence in context: A071412 A080884 A091392 * A002325 A129134 A133693
Adjacent sequences: A036574 A036575 A036576 * A036578 A036579 A036580
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KEYWORD
| nonn
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AUTHOR
| N. J. A. Sloane (njas(AT)research.att.com).
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