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 A059139 #13 May 20 2014 14:52:31
%S A059139 4,7,4,10,4,7,4,13,4,7,4,10,4,7,4,16,4,7,4,10,4,7,4,13,4,7,4,10,4,7,4,
%T A059139 19,4,7,4,10,4,7,4,13,4,7,4,10,4,7,4,16,4,7,4,10,4,7,4,13,4,7,4,10,4,
%U A059139 7,4,22,4,7,4,10,4,7,4,13,4,7,4,10,4,7,4,16,4,7,4,10,4,7,4,13,4,7,4,10,4
%N A059139 A hierarchical sequence (W2{2}*c - see A059126).
%C A059139 Let the general sequence H(a,b,n) = a*A007814(n+1) + b, then this sequence is H(3,4). Other hierarchical sequences of this type are A059132 (H(6,4)), A059141 (H(7,11)), A059144 (H(9,15)), A059134 (H(21,11)), A059137 (H(36,18)).
%H A059139 Ralf Stephan, <a href="/somedcgf.html">Some divide-and-conquer sequences ...</a>
%H A059139 J. Wallgren, <a href="/A059126/a059126.txt">Hierarchical sequences</a>
%F A059139 a(n) = 4 + 3*A007814(n). a(2n) = 4, a(2n+1) = a(n) + 3. - _Ralf Stephan_, Oct 09 2003
%K A059139 easy,nonn
%O A059139 0,1
%A A059139 _Jonas Wallgren_, Jan 19 2001