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 A099994 #6 Mar 30 2012 17:37:42
%S A099994 0,2,4,6,8,11,33,55,77,99,111,131,151,171,191,212,232,252,272,292,313,
%T A099994 333,353,373,393,414,434,454,474,494,515,535,555,575,595,616,636,656,
%U A099994 676,696,717,737,757,777,797,818,838,858,878,898,919,939,959,979,999,1111,1331,1551,1771,1991
%N A099994 Bisection of A002113.
%t A099994 r[n_]:=FromDigits[Reverse[IntegerDigits[n]]];v={}; Do[If[r[n]==n, v=Append[v, n]], {n, 0, 2200}];Table[v[[2k-1]], {k, Floor[Length[v]]/2}]
%K A099994 nonn,base,easy
%O A099994 1,2
%A A099994 _N. J. A. Sloane_, Nov 20 2004
%E A099994 Extended with Mathematica program by _Farideh Firoozbakht_, Dec 01 2004