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 A099820 #9 Aug 20 2019 11:22:32 %S A099820 0,10,100,110,1000,1010,1100,1110,10000,10010,10100,10110,11000,11010, %T A099820 11100,11110,100000,100010,100100,100110,101000,101010,101100,101110, %U A099820 110000,110010,110100,110110,111000,111010,111100,111110,1000000 %N A099820 Even nonnegative integers in base 2 (bisection of A007088). %H A099820 <a href="/index/Ar#2-automatic">Index entries for 2-automatic sequences</a>. %p A099820 seq(convert(2*n,binary),n=0..37); # _Emeric Deutsch_, Dec 15 2004 %Y A099820 Cf. A007088, A099821. %K A099820 nonn,easy %O A099820 0,2 %A A099820 _N. J. A. Sloane_, Nov 19 2004 %E A099820 More terms from _Emeric Deutsch_, Dec 15 2004