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 A059156 #12 Sep 13 2022 20:41:47
%S A059156 4,16,4,64,256,64,4,16,4,1024,4096,1024,4,16,4,64,256,64,4,16,4,16384,
%T A059156 65536,16384,4,16,4,64,256,64,4,16,4,1024,4096,1024,4,16,4,64,256,64,
%U A059156 4,16,4,262144,1048576,262144,4,16,4,64,256,64,4,16,4,1024,4096,1024,4
%N A059156 A hierarchical sequence (W'3{2,2}c - see A059126).
%H A059156 Jonas Wallgren, <a href="/A059126/a059126.txt">Hierarchical sequences</a>
%F A059156 a(n) = A059148(3*n) + A059148(3*n+1) + A059148(3*n+2). - _Sean A. Irvine_, Sep 13 2022
%Y A059156 Cf. A059126, A059148.
%K A059156 easy,nonn
%O A059156 0,1
%A A059156 _Jonas Wallgren_, Feb 02 2001