This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A143668 #24 Dec 26 2024 10:42:16 %S A143668 0,1,0,2,1,2,1,2,0,1,0,2,1,2,1,2,0,1,0,1,0,2,1,2,0,1,0,1,0,2,1,2,0,1, %T A143668 0,1,0,2,1,2,1,2,0,1,0,2,1,2,1,2,0,1,0,1,0,2,1,2,0,1,0,1,0,2,1,2,0,1, %U A143668 0,1,0,2,1,2,1,2,0,1,0,2,1,2,1,2,0,1,0,2,1,2,1,2,0,1,0,1,0,2,1,2 %N A143668 Result of the morphing 01->01021212, 02->0102121201, 12->01021201, iterated from '01'. Sequence of the Fibonacci word fractal. %C A143668 Letter '2' is always in an even position and '0' an odd position. %C A143668 When replacing '2' by '0', equals the infinite Fibonacci word (see A003849). %C A143668 This sequence produces the Fibonacci word fractal when applying the following turtle graphics rules: 0->draw segment+turn right, 1-> draw segment, 2-> draw segment+turn left (A. Monnerot-Dumaine 2008 see links). %C A143668 This sequence is the [1->12, 2->01, 3->02]-transform of A123564. - _Michel Dekking_, Mar 03 2018 %D A143668 M. Lothaire, Combinatorics on words, Cambridge University press. %H A143668 Alexis Monnerot-Dumaine, <a href="https://hal.archives-ouvertes.fr/hal-00367972"> The Fibonacci Word Fractal</a>, HAL Id : hal-00367972, 2009. %H A143668 Alexis Monnerot-Dumaine, <a href="/A171587/a171587.pdf">The Fibonacci word fractal</a> [Cached copy, with permission] %F A143668 Let (b(n)) be the infinite Fibonacci word. if (b(n)=0 and n is even), then a(n)=2, else a(n)=b(n). %Y A143668 Cf. A003849, A123564. %K A143668 nonn %O A143668 1,4 %A A143668 _Alexis Monnerot-Dumaine_, Aug 28 2008