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 A189664 Fixed point of the morphism 0->010, 1->001. 8
 0, 1, 0, 0, 0, 1, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 0, 1, 0, 1, 0, 0, 0, 1, 0, 1, 0, 0, 1, 0, 0, 0, 1, 0, 1, 0, 0, 1, 0, 0, 0, 1, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 0, 1, 0, 1, 0, 0, 0, 1, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 0, 1, 0, 1, 0, 0, 0, 1, 0, 1, 0, 0, 1, 0, 0, 0, 1, 0, 1, 0, 0, 1, 0, 0, 1, 0, 0, 0, 1, 0, 1, 0, 0, 0, 1, 0, 1, 0, 0, 1, 0, 0, 0, 1, 0, 1, 0, 0, 1, 0, 0, 1 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1 COMMENTS a(n) is the parity of the number of ternary 1-digits below the lowest 0-digit in the ternary expansion of n-1. All fixed-width morphisms have a similar digital interpretation. - Kevin Ryde, Apr 26 2017 LINKS Joerg Arndt, Table of n, a(n) for n = 1..2187 FORMULA a(3k-2)=0, a(3k-1)=1-a(k), a(3k)=a(k) for k>=1, a(0)=0. 2*a(n) = A284794(n) for n>=1. - Clark Kimberling, Apr 14 2017 a(n) = A284777(n) - 2n. - Clark Kimberling, Apr 15 2017 EXAMPLE Iterating the morphism starting with 0: 0:   (#=1)   0 1:   (#=3)   010 2:   (#=9)   010001010 3:   (#=27)   010001010010010001010001010 4:   (#=81)   010001010010010001010001010010001010010001010010010001010001010010010001010001010 etc. MATHEMATICA t = Nest[Flatten[# /. {0->{0, 1, 0}, 1->{0, 0, 1}}] &, {0}, 5] (*A189664*) f[n_] := t[[n]] Flatten[Position[t, 0]] (*A189665*) Flatten[Position[t, 1]] (*A189666*) s[n_] := Sum[f[i], {i, 1, n}]; s[0] = 0; Table[s[n], {n, 1, 120}] (*A189667*) Nest[Flatten[# /. a_Integer -> {0, Abs[a - 1], a}] &, {0}, 5] (* Robert G. Wilson v, Jul 16 2012 *) CROSSREFS Cf. A189628, A189665, A189666, A189667. Sequence in context: A134667 A117943 A285969 * A260446 A096268 A219097 Adjacent sequences:  A189661 A189662 A189663 * A189665 A189666 A189667 KEYWORD nonn AUTHOR Clark Kimberling, Apr 25 2011 STATUS approved

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Last modified June 17 15:28 EDT 2019. Contains 324194 sequences. (Running on oeis4.)