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 A066334 #5 Feb 03 2020 15:23:47 %S A066334 0,1,10,11,100,101,110,111,1110,1111,-1,-1,-1,-1,-1,-1,10000,10001, %T A066334 10010,10011,10100,10101,10110,10111,11110,11111,-1,-1,-1,-1,-1,-1, %U A066334 100000,100001,100010,100011,100100,100101,100110,100111,101110,101111,-1,-1,-1,-1,-1,-1,110000,110001,110010,110011 %N A066334 Binary string which equals n when 1's, 2's, 4's and 8's bits have weights 1, 2, 4, 2 respectively, while the other bits have their usual weights. -1 if no such string exists. %D A066334 Morris M. Mano, Digital Design, Prentice Hall, 2002. p. 20. %Y A066334 Cf. A066335. %K A066334 easy,sign %O A066334 0,3 %A A066334 _George E. Antoniou_, Dec 15 2001 %E A066334 More terms from _Joshua Zucker_, Jun 21 2006