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 A195168 #12 Sep 08 2022 08:45:59
%S A195168 0,3,5,8,10,13,15,18,20,23,25,28,30,32,35,37,40,42,45,47,50,52,55,57,
%T A195168 60,62,64,67,69,72,74,77,79,82,84,87,89,92,94,96,99,101,104,106,109,
%U A195168 111,114,116,119,121,124,126,128,131,133,136,138,141,143,146,148
%N A195168 a(n) = 3*n - floor(n*r/3), where r=(1+sqrt(5))/2 (the golden ratio).
%H A195168 Vincenzo Librandi, <a href="/A195168/b195168.txt">Table of n, a(n) for n = 0..10000</a>
%t A195168 With[{c = GoldenRatio},Table[3*n - Floor[c*n/3],{n,0,50}]] (* _G. C. Greubel_, Oct 31 2017 *)
%o A195168 (Magma) [3*n-Floor(n*(1+Sqrt(5))/6): n in [0..70]]; // _Vincenzo Librandi_, Sep 11 2011
%o A195168 (PARI) for(n=0,50, print1(3*n - floor(n*(1+sqrt(5))/6), ", ")) \\ _G. C. Greubel_, Oct 31 2017
%K A195168 nonn
%O A195168 0,2
%A A195168 _Clark Kimberling_, Sep 10 2011