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 A103849 #4 Mar 30 2012 17:26:11 %S A103849 0,112,1,2,121,3,4,134,5,6,143,7,8,156,9,12,165,10,14,178,11,16,187, %T A103849 13,18,211,15,20,314,17,21,336,19,22,341,23,24,358,25,26,363,27,28, %U A103849 385,29,34,413,30,36,431,31,38,516,32,40,538,33,41,561,35,42,583,37,43,615,39 %N A103849 Rearrangement of natural numbers according to sums of odd and even digits. %C A103849 Sum of odd digits (less than, equals and larger than) sum of even digits A103829, A036301, 103848. %F A103849 n=3k-2, a(n)=A103829(k); n=3k-1, a(n)=A036301(k); n=3k-1, a(n)=A103848(k); (k=1, 2, ...) %e A103849 k=1: a(1)=A103829(1), a(2)=A036301(1), a(3)=A103848(1). %Y A103849 Cf. A036301, A103829, A103848. %K A103849 nonn,base %O A103849 1,2 %A A103849 _Zak Seidov_, Feb 18 2005