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 A133479 #23 Jan 02 2024 08:55:07
%S A133479 1,2,10,26,106,314,1162,3674,12970,42362,146122,485018,1653994,
%T A133479 5534138,18766090,63039194,213167914,717481466,2422824778,8162676506,
%U A133479 27545274730,92846686778,313208884618,1055982378842,3561653455786
%N A133479 a(n) = a(n-1) + 8*a(n-2) for n >= 2, a(0)=1, a(1)=2.
%H A133479 <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (1,8).
%F A133479 G.f.: (1+x)/(1-x-8*x^2).
%F A133479 a(n) = Sum_{k=0..n+1} A122950(n+1,k)*7^(n+1-k). - _Philippe Deléham_, Jan 08 2008
%F A133479 a(n) = ((11+sqrt(33))/22)*(1/2 + (1/2)*sqrt(33))^n + ((11-sqrt(33))/22)*(1/2 - (1/2)*sqrt(33))^n. - _Richard Choulet_, Nov 20 2008
%K A133479 easy,nonn
%O A133479 0,2
%A A133479 _Philippe Deléham_, Jan 03 2008