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 A039984 #19 Jul 08 2025 22:42:40 %S A039984 1,0,1,1,1,1,0,0,1,1,0,0,1,1,1,1,1,1,0,0,1,1,1,1,1,1,0,0,1,1,0,0,1,1, %T A039984 0,0,1,1,1,1,1,1,0,0,1,1,0,0,1,1,0,0,1,1,1,1,1,1,0,0,1,1,1,1,1,1,0,0, %U A039984 1,1,1,1,1,1,0,0,1,1,0,0,1,1,0,0,1,1,1,1,1,1,0,0,1,1,1,1,1,1,0,0,1,1,1,1,1 %N A039984 An example of a d-perfect sequence. %C A039984 Image, under the coding a,c,d -> 1, b -> 0, of the fixed point, starting with a, of the morphism a -> ab, b -> cd, c -> cd, d -> bb. - _Jeffrey Shallit_, May 15 2016 %H A039984 D. Kohel, S. Ling and C. Xing, <a href="http://www.maths.usyd.edu.au/u/kohel/doc/perfect.ps">Explicit Sequence Expansions</a>, in Sequences and their Applications, C. Ding, T. Helleseth, and H. Niederreiter, eds., Proceedings of SETA'98 (Singapore, 1998), 308-317, 1999. DOI: 10.1007/978-1-4471-0551-0_23 %F A039984 a(n) = A090345(n) mod 2. - _Christian G. Bower_, Jun 12 2005 %K A039984 nonn %O A039984 1,1 %A A039984 _N. J. A. Sloane_ %E A039984 More terms from _Christian G. Bower_, Jun 12 2005