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 A255216 #17 Oct 23 2023 11:37:33
%S A255216 1,1,1,2,3,4,5,7,10,14,18,25,34,45,61,82,110,147,198,266,357,479,642,
%T A255216 862,1156,1552,2082,2793,3748,5028,6746,9051,12143,16292,21859,29327,
%U A255216 39346,52788,70823,95019,127482,171035,229468,307863,413042,554155,743477,997479,1338258
%N A255216 a(n) = floor((3/sqrt(5))^n).
%C A255216 a(n) is the total length (rounded down to integer) of the elements of a variant of a 3-element fractal after n iterations, starting with 3 elements, each of whose length is 1/3 (in some units). See illustration in the links.
%H A255216 Harvey P. Dale, <a href="/A255216/b255216.txt">Table of n, a(n) for n = 0..1000</a>
%H A255216 Kival Ngaokrajang, <a href="/A255216/a255216_1.pdf">Illustration of initial terms</a>
%F A255216 a(n) = floor((3/sqrt(5))^n).
%t A255216 With[{c=3/Sqrt[5]},Table[Floor[c^n],{n,0,50}]] (* _Harvey P. Dale_, Oct 23 2023 *)
%o A255216 (PARI){for(n=0,100,a=floor((3/sqrt(5))^n);print1(a,", "))}
%Y A255216 Cf. A017919.
%K A255216 nonn
%O A255216 0,4
%A A255216 _Kival Ngaokrajang_, Feb 25 2015