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 A167677 #6 Mar 31 2017 20:37:15
%S A167677 2,2,1,1,2,1,2,1,2,2,22,22,21,21,22,21,22,21,22,22,12,12,11,11,12,11,
%T A167677 12,11,12,12,12,12,11,11,12,11,12,11,12,12,22,22,21,21,22,21,22,21,22,
%U A167677 22,12,12,11,11,12,11,12,11,12,12,22,22,21,21,22,21,22,21,22,22,12,12,11
%N A167677 Replace prime digits with 1 and nonprime digits with 2.
%t A167677 Table[FromDigits[If[PrimeQ[ # ],1,2]&/@IntegerDigits[n]],{n,0,200}]
%Y A167677 Cf. A065031, A167678, A167679.
%K A167677 base,nonn
%O A167677 0,1
%A A167677 _Zak Seidov_, Nov 09 2009