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 A154252 #25 Jan 01 2024 08:34:13
%S A154252 1,2,12,32,72,152,312,632,1272,2552,5112,10232,20472,40952,81912,
%T A154252 163832,327672,655352,1310712,2621432,5242872,10485752,20971512,
%U A154252 41943032,83886072,167772152,335544312,671088632,1342177272,2684354552,5368709112,10737418232
%N A154252 Expansion of (1-x+8x^2)/((1-x)(1-2x)) .
%C A154252 Binomial transform of 1,1,9,1,9,1,9,1,9,1,9,1,9,1,9,...
%H A154252 G. C. Greubel, <a href="/A154252/b154252.txt">Table of n, a(n) for n = 0..1000</a>
%H A154252 <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (3,-2).
%F A154252 a(n) = 3*a(n-1) - 2*a(n-2), n>2, with a(0)=1, a(1)=2, a(2)=12.
%F A154252 a(n) = 2*a(n-1) + 8, n>1, with a(0)=1, a(1)=2.
%F A154252 a(n) = 10*2^(n-1) - 8, n>=1, with a(0)=1.
%F A154252 E.g.f.: 5*exp(2*x) - 8*exp(x) + 4. - _G. C. Greubel_, Sep 08 2016
%t A154252 Join[{1},LinearRecurrence[{3,-2},{2,12},40]] (* _Harvey P. Dale_, Dec 30 2014 *)
%t A154252 Join[{1},Table[5*2^n - 8, {n,1,25}]] (* _G. C. Greubel_, Sep 08 2016 *)
%o A154252 (PARI) Vec((1-x+8*x^2)/((1-x)*(1-2*x))+O(x^99)) \\ _Charles R Greathouse IV_, Sep 26 2012
%Y A154252 Cf.: A094373, A000079, A083329, A095121, A154117, A131128, A154118, A131130, A154251
%K A154252 nonn,easy
%O A154252 0,2
%A A154252 _Philippe Deléham_, Jan 05 2009
%E A154252 Two terms corrected by _Johannes W. Meijer_, May 26 2011