A214317 a(n) = length-n prefix of the Fibonacci word A003842.

1, 12, 121, 1211, 12112, 121121, 1211212, 12112121, 121121211, 1211212112, 12112121121, 121121211211, 1211212112112, 12112121121121, 121121211211212, 1211212112112121, 12112121121121211, 121121211211212112, 1211212112112121121, 12112121121121211212

Offset

1,2

Links

Alois P. Heinz, Table of n, a(n) for n = 1..300

Maple

S:= proc(n) option remember;
      `if`(n<2, [2-n], [S(n-1)[], S(n-2)[]])
    end:
a:= proc(n) local k;
      for k while nops(S(k))<n do od;
      parse(cat(S(k)[1..n][]))
    end;
seq(a(n), n=1..30);  # Alois P. Heinz, Jul 19 2012

Mathematica

S = SubstitutionSystem[{1 -> {1, 2}, 2 -> {1}}, {1}, 20];
FromDigits[Take[#[[1]], #[[2]]]]& /@ Transpose[{S, Range[Length[S]]}] (* Jean-François Alcover, Nov 07 2020 *)

Crossrefs

Cf. A003842, A214318.

Sequence in context: A176779 A098297 A037543 * A037487 A332603 A358615

Adjacent sequences: A214314 A214315 A214316 * A214318 A214319 A214320

Keyword

nonn

Author

N. J. A. Sloane, Jul 12 2012

Status

approved