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 A121967 #6 Mar 30 2012 19:00:47
%S A121967 1,0,1,1,1,1,0,1,0,0,1,1,0,1,0,0,1,0,1,0,1,1,1,0,1,1,1,0,1,1,0,0,0,0,
%T A121967 0,1,1,1,1,0,0,1,1,1,0,0,0,1,0,1,1,0,1,1,0,1,1,1,0,0,1,0,1,0,1,1,0,1,
%U A121967 0,1,0,1,0,0,0,1,1,0,0,0,0,0,0,0,0,0,1,1,1,0,0,0,0,1,1,1,0,1,0,0,1,0,0,0,0
%N A121967 Binary expansion of root of cos x = x.
%t A121967 BaseForm[FindRoot[Cos[x] == x, {x, {1}}, WorkingPrecision -> 1000], 2]
%Y A121967 Cf. A003957.
%K A121967 base,cons,nonn
%O A121967 1,1
%A A121967 _Ben Branman_, Sep 25 2008