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 A298417 #4 Feb 11 2018 10:52:47
%S A298417 1,1,1,5,13,37,105,289,801,2193,6025,16473,45101,123253,336997,920789,
%T A298417 2516373,6875125,18785189,51322821,140222045,383095757,1046652077,
%U A298417 2859512141,7812373537,21343816457,58312503241,159312762649,435250868777,1189127599849
%N A298417 a(n) = 2*a(n-1) + 2*a(n-2) + a([n/2]), where a(0) = 1, a(1) = 1, a(2) = 1.
%C A298417 a(n)/a(n-1) -> 1+sqrt(3).
%H A298417 Clark Kimberling, <a href="/A298417/b298417.txt">Table of n, a(n) for n = 0..1000</a>
%t A298417 a[0] = 1; a[1] = 1; a[2] = 1;
%t A298417 a[n_] := a[n] = 2 a[n - 1] + 2 a[n - 2] + a[Floor[n/2]];
%t A298417 Table[a[n], {n, 0, 30}] (* A298417 *)
%Y A298417 Cf. A298338, A298416.
%K A298417 nonn,easy
%O A298417 0,4
%A A298417 _Clark Kimberling_, Feb 11 2018