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 A175541 #8 Nov 21 2013 12:50:02
%S A175541 10,101,1011,10111,101111,10111111,101111111,1011111111111,
%T A175541 10111111111111111111,101111111111111111111111111111111111,
%U A175541 1011111111111111111111111111111111111111
%N A175541 A007505 in binary.
%C A175541 Primes of the form 10, 101, 1011, 10111,..
%F A175541 A002235(n)=A091997(n)-A000012(n)=A000120(A007505(n))-A023416(A007505(n)).
%e A175541 a(12)=101111111111111111111111111111111111111111111.
%t A175541 FromDigits/@Select[Table[PadRight[{1,0},n,1],{n,0,50}], PrimeQ[ FromDigits[ #,2]]&] (* _Harvey P. Dale_, Nov 12 2011 *)
%K A175541 nonn,base
%O A175541 1,1
%A A175541 _Juri-Stepan Gerasimov_, Jun 24 2010