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 A066106 #14 Feb 03 2020 15:32:19
%S A066106 0,4,8,8,24,12,48,16,80,20,120,24,168,28,224,32,288,36,360,40,440,44,
%T A066106 528,48,624,52,728,56,840,60,960,64,1088,68,1224,72,1368,76,1520,80,
%U A066106 1680,84,1848,88,2024,92,2208,96,2400,100,2600,104,2808,108,3024,112
%N A066106 a(2n) = (2n)(2n+2); a(2n+1) = 4n + 4.
%H A066106 Harry J. Smith, <a href="/A066106/b066106.txt">Table of n, a(n) for n = 0..1000</a>
%H A066106 <a href="/index/Rec#order_06">Index entries for linear recurrences with constant coefficients</a>, signature (0,3,0,-3,0,1).
%F A066106 G.f.: 4*x*(-1-2*x+x^2) / ( (x-1)^3*(1+x)^3 ). - _Len Smiley_, Dec 06 2001
%F A066106 a(n) = 4*A129889(n+1). - _R. J. Mathar_, Oct 31 2015
%t A066106 Flatten[Table[{(2n)(2n+2),4n+4},{n,0,30}]] (* _Harvey P. Dale_, May 14 2011 *)
%o A066106 (PARI) { for (n=0, 1000, if(n%2, a=2*n + 2, a=n*(n + 2)); write("b066106.txt", n, " ", a) ) } \\ _Harry J. Smith_, Nov 15 2009
%K A066106 easy,nonn
%O A066106 0,2
%A A066106 _George E. Antoniou_, Dec 05 2001