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 A097150 #3 Mar 30 2012 17:36:43
%S A097150 0,1,2,3,4,1,-5,1,-4,1,-3,1,-2,1,-1,1,0,1,1,1,2,1,3,1,4,2,-5,2,-4,2,
%T A097150 -3,2,-2,2,-1,2,0,2,1,2,2,2,3,2,4,3,-5,3,-4,3,-3,3,-2,3,-1,3,0,3,1,3,
%U A097150 2,3,3,3,4,4,-5,4,-4,4,-3,4,-2,4,-1,4,0,4,1,4,2,4,3,4,4,1,-5,-5,1,-5,-4,1,-5,-3,1,-5,-2,1,-5,-1,1,-5,0,1,-5,1,1,-5,2,1,-5,3
%N A097150 Digits of balanced base-10 representations of nonnegative integers (most significant digits first).
%C A097150 See full definition, its source and another example in A097151.
%e A097150 As the only digits permissible are in {-5,-4,-3,-2,-1,0,1,2,3,4}, 5 = 1*10 - 5 is the first number requiring two of these digits: 1,-5.
%Y A097150 A097151 is the same sequence but with the digits in reverse order.
%K A097150 base,easy,sign
%O A097150 1,3
%A A097150 _Rick L. Shepherd_, Jul 27 2004