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 A132134 #5 Jan 04 2013 17:59:49 %S A132134 1,2,3,4,6,9,11,15,18,27,29,30,32,33,35,42,45,54,60,81,83,86,87,89,92, %T A132134 95,96,98,99,101,104,105,107,123,126,135,141,153,162,243,245,248,249, %U A132134 251,252,254,257,258,260,261,263,266,267,269,275,276,278,285,287,288 %N A132134 Base 3 "Punctual Bird" numbers: write the natural numbers, base 3, in a string 12101112202122100101102... Sequence gives numbers which do not occur in the string ahead of their natural place. %e A132134 a(5)=6 because 6 (20, base 3) is the fifth number that appears first in its "natural" place in the string of concatenated base-3 numbers. %Y A132134 Cf. A033307, A117804, A116700, A131881, A132131, A132132, A132133, A132135. %K A132134 nonn,base %O A132134 1,2 %A A132134 _Graeme McRae_, Aug 11 2007