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A272664 (001)(001)(001)(10)*. 1
0, 0, 1, 0, 0, 1, 0, 0, 1, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0 (list; graph; refs; listen; history; text; internal format)
OFFSET

0

COMMENTS

Three copies of 001 followed by infinitely many copies of 10.

Lexicographically least binary sequence containing no subblock of the form S S reverse(S).

LINKS

Colin Barker, Table of n, a(n) for n = 0..1000

Jeffery Shallit, Experimental Combinatorics on Words Using the Walnut Prover, Talk Presented at Computational Discovery in Mathematics (ACMES 2), University of Western Ontario, May 12 2016

Index entries for linear recurrences with constant coefficients, signature (0,1).

FORMULA

From Colin Barker, May 16 2016: (Start)

a(n) = (1-(-1)^n)/2 for n>8.

a(n) = a(n-2) for n>10.

G.f.: x^2*(1+x^3-x^4)*(1-x^2+x^4) / ((1-x)*(1+x)).

(End)

PROG

(PARI) concat(vector(2), Vec(x^2*(1+x^3-x^4)*(1-x^2+x^4)/((1-x)*(1+x)) + O(x^50))) \\ Colin Barker, May 16 2016

CROSSREFS

Cf. A241903.

Sequence in context: A072785 A188297 A289128 * A074937 A143518 A122414

Adjacent sequences:  A272661 A272662 A272663 * A272665 A272666 A272667

KEYWORD

nonn,easy

AUTHOR

N. J. A. Sloane, May 15 2016

STATUS

approved

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Last modified July 17 23:21 EDT 2019. Contains 325109 sequences. (Running on oeis4.)