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 A037459 #9 Mar 30 2012 18:56:28
%S A037459 1,2,3,5,6,7,8,10,11,12,13,15,16,17,18,25,26,27,28,30,31,32,33,35,36,
%T A037459 37,38,40,41,42,43,50,51,52,53,55,56,57,58,60,61,62,63,65,66,67,68,75,
%U A037459 76,77,78,80,81,82,83,85,86,87,88,90,91,92,93
%N A037459 Sum{d(i)*5^i: i=0,1,...,m}, where Sum{d(i)*4^i: i=0,1,...,m} is the base 4 representation of n.
%F A037459 A020654 \ {0}. [From _R. J. Mathar_, Oct 20 2008]
%K A037459 nonn,base
%O A037459 1,2
%A A037459 _Clark Kimberling_