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 A212262 #20 Sep 08 2022 08:46:02
%S A212262 1,4,10,29,84,248,737,2200,6582,19717,59104,177236,531585,1594556,
%T A212262 4783346,14349517,43047708,129141760,387423073,1162265648,3486791166,
%U A212262 10460364149,31381077320,94143207484,282429582849,847288684468,2541865949722,7625597681405
%N A212262 a(n) = 3^n + Fibonacci(n).
%H A212262 Bruno Berselli, <a href="/A212262/b212262.txt">Table of n, a(n) for n = 0..1000</a>
%H A212262 <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (4,-2,-3).
%F A212262 G.f.: (1-2*x)*(1+2*x)/((1-3*x)*(1-x-x^2)).
%t A212262 Table[3^n + Fibonacci[n], {n, 0, 27}]
%o A212262 (PARI) for(n=0, 27, print1(3^n+fibonacci(n)", "));
%o A212262 (Magma) [3^n+Fibonacci(n): n in [0..27]];
%o A212262 (Sage) [3^n +fibonacci(n) for n in (0..30)] # _G. C. Greubel_, Jul 05 2021
%Y A212262 Cf. A000045, A000244, A001611, A117591, A212323.
%K A212262 nonn,easy
%O A212262 0,2
%A A212262 _Bruno Berselli_, May 08 2012