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 A214068 #17 Feb 17 2024 12:23:50
%S A214068 0,1,4,6,9,10,13,15,18,19,22,24,27,28,31,33,36,37,40,42,45,46,49,51,
%T A214068 54,55,58,60,63,64,67,69,72,73,76,78,81,82,85,87,90,91,94,96,99,100,
%U A214068 103,105,108,109,112,114,117,118,121,123,126
%N A214068 a(n) = floor((3/2)*floor((3/2)*n)).
%C A214068 Also, numbers congruent to {0,1,4,6} mod 9.
%H A214068 Clark Kimberling, <a href="/A214068/b214068.txt">Table of n, a(n) for n = 0..1000</a>
%H A214068 <a href="/index/Rec#order_05">Index entries for linear recurrences with constant coefficients</a>, signature (1,0,0,1,-1).
%F A214068 a(n) = (18*n - 5 + 3*(-1)^n + (1 - i)*(-i)^n + (1 + i)*i^n)/8, where i = sqrt(-1).
%F A214068 a(n) = a(n-1) + a(n-4) - a(n-5).
%F A214068 G.f.: (x*(1 + 3*x + 2*x^2 + 3*x^3))/(1 - x - x^4 + x^5).
%t A214068 f[n_]:=Floor[(3/2)Floor[3n/2]];
%t A214068 t=Table[f[n],{n,0,70}]
%t A214068 LinearRecurrence[{1,0,0,1,-1},{0,1,4,6,9},60] (* _Harvey P. Dale_, Jun 21 2021 *)
%Y A214068 Cf. A214066, A214067.
%K A214068 nonn,easy
%O A214068 0,3
%A A214068 _Clark Kimberling_, Jul 20 2012