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 A129197 #17 Sep 30 2020 14:46:02
%S A129197 12,3,4,3,12,1,12,3,4,3,12,1,12,3,4,3,12,1,12,3,4,3,12,1,12,3,4,3,12,
%T A129197 1,12,3,4,3,12,1,12,3,4,3,12,1,12,3,4,3,12,1,12,3,4,3,12,1,12,3,4,3,
%U A129197 12,1,12,3,4,3,12,1,12,3,4,3,12,1,12,3,4,3,12,1
%N A129197 a(n) = numerator( 3*(3+(-1)^n)/(n+1)^3 ).
%C A129197 Denominator of 3*(3+(-1)^n)/(n+1)^3 is A129196.
%H A129197 <a href="/index/Rec#order_06">Index entries for linear recurrences with constant coefficients</a>, signature (0,0,0,0,0,1).
%F A129197 G.f.: (12 + 3*x + 4*x^2 + 3*x^3 + 12*x^4 + x^5)/(1 - x^6).
%F A129197 Period 6: repeat [12, 3, 4, 3, 12, 1].
%t A129197 Table[3 (3+(-1)^n)/(n+1)^3,{n,0,80}]//Numerator (* _Harvey P. Dale_, Sep 26 2020 *)
%Y A129197 Cf. sequences listed in Comments section of A283393.
%K A129197 nonn,easy
%O A129197 0,1
%A A129197 _Paul Barry_, Apr 02 2007