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A221155 The generalized Fibonacci words q_n^[4]. 4
1, 1313, 13133, 131331313, 13133131331311, 13133131331311313113131, 1313313133131131311313113133131331311, 131331313313113131131311313313133131131311313113133131331313 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

LINKS

Lars Blomberg, Table of n, a(n) for n = 0..12

José L. Ramírez, Gustavo N. Rubiano, and Rodrigo de Castro, A Generalization of the Fibonacci Word Fractal and the Fibonacci Snowflake, arXiv preprint arXiv:1212.1368 [cs.DM], 2012.

MATHEMATICA

bar[a_List] := a /. {1 -> 3, 3 -> 1};

q[0, _] = {}; q[1, _] = {1}; q[2, i_] := If[EvenQ[i], Table[{1, 3}, {i/2}], Append[Table[{1, 3}, {(i-1)/2}], 1]] // Flatten;

q[n_, i_] := q[n, i] = If[EvenQ[i], If[Mod[n, 3] == 1, Join[q[n-1, i], q[n-2, i]], Join[q[n-1, i], q[n-2, i] // bar]], If[Mod[n, 3] == 0, Join[q[n-1, i], q[n-2, i]], Join[q[n-1, i], q[n-2, i] // bar]]];

a[n_] := q[n+1, 4] // FromDigits;

Table[a[n], {n, 0, 7}] (* Jean-François Alcover, Oct 02 2018 *)

CROSSREFS

Cf. A221153, A221154, A221155, A221156.

Sequence in context: A223612 A223413 A333407 * A237393 A242151 A260765

Adjacent sequences:  A221152 A221153 A221154 * A221156 A221157 A221158

KEYWORD

nonn

AUTHOR

N. J. A. Sloane, Jan 04 2013

EXTENSIONS

a(5)-a(7) from Lars Blomberg, Sep 04 2017

STATUS

approved

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Last modified November 29 21:32 EST 2021. Contains 349416 sequences. (Running on oeis4.)