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 A059155 #15 Jul 02 2023 16:22:55
%S A059155 12,120,1008,8160,65472,524160,4194048,33553920,268434432,2147481600,
%T A059155 17179865088,137438945280,1099511611392,8796092989440,70368744112128,
%U A059155 562949953290240,4503599627108352,36028797018439680,288230376150663168,2305843009211596800,18446744073705357312
%N A059155 A hierarchical sequence (S(W'2{3}c) - see A059126).
%H A059155 Vincenzo Librandi, <a href="/A059155/b059155.txt">Table of n, a(n) for n = 0..200</a>
%H A059155 J. Wallgren, <a href="/A059126/a059126.txt">Hierarchical sequences</a>
%H A059155 <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (10, -16).
%F A059155 G.f.: 12/((8*x-1)*(2*x-1)). [Maksym Voznyy (voznyy(AT)mail.ru), Jul 27 2009]
%F A059155 a(n) = 2^(n+2)*(4^(n+1)-1). - _Peter Luschny_, May 08 2014
%t A059155 CoefficientList[Series[12/((8 x - 1) (2 x - 1)), {x, 0, 40}], x] (* _Vincenzo Librandi_, May 09 2014 *)
%K A059155 nonn,easy
%O A059155 0,1
%A A059155 _Jonas Wallgren_, Feb 02 2001
%E A059155 More terms from _Peter Luschny_, May 08 2014