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 A004286 #13 Jan 02 2016 04:15:57
%S A004286 1,10,10,100,11111,10,11,1000,100,111110,1101,100,10111,110,111110,
%T A004286 10000,11001,100,101011,1111100,110,11010,1101,1000,111101,101110,
%U A004286 1000,1100,1010111,111110,1001,100000,11010,110010,1111111111,100,101,1010110,101110,11111000
%N A004286 Least positive multiple of n written in base 6 using only 0 and 1.
%o A004286 (PARI) a(n) = {k=1; while (vecmax(digits(k*n, 6)) != 1, k++); subst(Pol(digits(k*n, 6)), x, 10);}
%K A004286 nonn,base
%O A004286 1,2
%A A004286 _David W. Wilson_
%E A004286 a(29) corrected by _Sean A. Irvine_, Dec 26 2015
%E A004286 More terms from _Michel Marcus_, Dec 27 2015