cp's OEIS Frontend

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.

A179969 Ordered list in decimal notation of the subwords appearing in the infinite Fibonacci word A005614.

Original entry on oeis.org

0, 1, 1, 2, 3, 2, 3, 5, 6, 5, 6, 10, 11, 13, 11, 13, 21, 22, 26, 27, 22, 26, 27, 43, 45, 53, 54, 45, 53, 54, 86, 90, 91, 107, 109, 90, 91, 107, 109, 173, 181, 182, 214, 218, 181, 182, 214, 218, 346, 347, 363, 365, 429, 437, 363, 365, 429, 437, 693, 694, 726, 730, 858, 859, 875, 726, 730, 858, 859, 875
Offset: 1

Views

Author

T. D. Noe, Jan 12 2011

Keywords

Comments

See A178992 for more details. In binary, the subwords are 0, 1, 01, 10, 11, 010, 011, 101, 110, 0101, 0110, 1010, 1011, 1101,... Converting these numbers to decimal produces this sequence. Except for the initial 0, subwords of the form 0X occur later in the sequence than X. Hence, the second occurrence of a number in this sequence represents the subword having a leading zero. There is a link to a file containing the subwords in binary.

Programs

  • Mathematica
    iter=8; f=Nest[Flatten[#/.{0->{1},1->{1,0}}]&,{1},iter]; u={}; n=1; While[lst={}; k=0; While[num=FromDigits[Take[f,{1,n}+k],2]; lst=Union[lst,{num}]; Length[lst]