%I #15 Jul 02 2023 16:22:55

%S 12,120,1008,8160,65472,524160,4194048,33553920,268434432,2147481600,

%T 17179865088,137438945280,1099511611392,8796092989440,70368744112128,

%U 562949953290240,4503599627108352,36028797018439680,288230376150663168,2305843009211596800,18446744073705357312

%N A hierarchical sequence (S(W'2{3}c) - see A059126).

%H Vincenzo Librandi, <a href="/A059155/b059155.txt">Table of n, a(n) for n = 0..200</a>

%H J. Wallgren, <a href="/A059126/a059126.txt">Hierarchical sequences</a>

%H <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (10, -16).

%F G.f.: 12/((8*x-1)*(2*x-1)). [Maksym Voznyy (voznyy(AT)mail.ru), Jul 27 2009]

%F a(n) = 2^(n+2)*(4^(n+1)-1). - _Peter Luschny_, May 08 2014

%t CoefficientList[Series[12/((8 x - 1) (2 x - 1)), {x, 0, 40}], x] (* _Vincenzo Librandi_, May 09 2014 *)

%K nonn,easy

%O 0,1

%A _Jonas Wallgren_, Feb 02 2001

%E More terms from _Peter Luschny_, May 08 2014