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 A059142 #32 Jul 02 2023 16:14:37
%S A059142 11,40,105,242,523,1092,2237,4534,9135,18344,36769,73626,147347,
%T A059142 294796,589701,1179518,2359159,4718448,9437033,18874210,37748571,
%U A059142 75497300,150994765,301989702,603979583,1207959352,2415918897,4831837994,9663676195,19327352604
%N A059142 A hierarchical sequence (S(W2{3}*) - see A059126).
%H A059142 Jonas Wallgren, <a href="/A059126/a059126.txt">Hierarchical sequences</a>
%H A059142 <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (4, -5, 2).
%F A059142 Conjectures from _Colin Barker_, Oct 06 2015: (Start)
%F A059142 a(n) = 4*a(n-1) - 5*a(n-2) + 2*a(n-3) for n > 2.
%F A059142 a(n) = (-25 + 9*2^(2+n) - 7*n).
%F A059142 G.f.: (4*x-11) / ((x-1)^2*(2*x-1)).
%F A059142 (End)
%Y A059142 Cf. A059126.
%K A059142 nonn
%O A059142 0,1
%A A059142 _Jonas Wallgren_, Jan 19 2001
%E A059142 More terms from _Sean A. Irvine_, Sep 13 2022