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 A135353 #30 Jan 11 2025 23:45:51
%S A135353 2,-3,3,22,51,93,170,333,675,1366,2739,5469,10922,21837,43683,87382,
%T A135353 174771,349533,699050,1398093,2796195,5592406,11184819,22369629,
%U A135353 44739242,89478477,178956963,357913942,715827891,1431655773,2863311530,5726623053,11453246115,22906492246
%N A135353 a(n) = 3*a(n-1) - 3*a(n-2) + 2*a(n-3), with a(0) = 2, a(1) = -3, a(2) = 3.
%C A135353 Sequence identical to its third differences. "Self-transform". Initial terms are transform's coefficients .
%H A135353 G. C. Greubel, <a href="/A135353/b135353.txt">Table of n, a(n) for n = 0..1000</a>
%H A135353 <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (3,-3,2).
%F A135353 a(n) = (8/3)*2^n - (2/3)*cos(Pi*n/3) - (16*sqrt(3)/3)*sin(Pi*n/3). - _Richard Choulet_, Jan 02 2008
%F A135353 G.f.: (2 - 9*x + 18*x^2)/((1-2*x)*(1-x+x^2)). - _Philippe Deléham_, Dec 29 2008
%t A135353 LinearRecurrence[{3,-3,2},{2,-3,3},30] (* or *) CoefficientList[Series[ (-2+9 x-18 x^2)/(-1+3 x-3 x^2+2 x^3),{x,0,30}],x] (* _Harvey P. Dale_, Apr 20 2011 *)
%K A135353 sign
%O A135353 0,1
%A A135353 _Paul Curtz_, Dec 07 2007
%E A135353 More terms from _Philippe Deléham_, Dec 29 2008