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 A033041 #8 Nov 21 2013 12:46:32 %S A033041 1,3,5,7,9,11,13,15,17,19,21,23,25,27,29,31,49,51,53,55,57,59,61,63, %T A033041 81,83,85,87,89,91,93,95,113,115,117,119,121,123,125,127,145,147,149, %U A033041 151,153,155,157,159,177,179,181,183,185,187,189 %N A033041 Numbers all of whose base 16 digits are odd. %t A033041 Select[Range[200],And@@OddQ[IntegerDigits[#,16]]&] (* _Harvey P. Dale_, Dec 13 2011 *) %K A033041 nonn,base %O A033041 1,2 %A A033041 _Clark Kimberling_