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 A298416 #4 Feb 11 2018 10:52:31
%S A298416 1,1,1,3,7,19,49,133,357,973,2641,7209,19651,53671,146511,400231,
%T A298416 1093127,2986359,8157999,22287743,60888843,166350531,454471539,
%U A298416 1241636931,3392197289,9267648789,25319638485,69174520877,188988172213,516325239669,1410626423533
%N A298416 a(n) = 2*a(n-1) + 2*a(n-2) - a([n/2]), where a(0) = 1, a(1) = 1, a(2) = 1.
%C A298416 a(n)/a(n-1) -> 1+sqrt(3).
%H A298416 Clark Kimberling, <a href="/A298416/b298416.txt">Table of n, a(n) for n = 0..1000</a>
%t A298416 a[0] = 1; a[1] = 1; a[2] = 1;
%t A298416 a[n_] := a[n] =+ 2 a[n - 1] + 2 a[n - 2] - a[Floor[n/2]];
%t A298416 Table[a[n], {n, 0, 30}] (* A298416 *)
%Y A298416 Cf. A298338, A298417.
%K A298416 nonn,easy
%O A298416 0,4
%A A298416 _Clark Kimberling_, Feb 11 2018