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 A173512 #14 Sep 08 2022 08:45:50
%S A173512 4,13,20,29,36,45,52,61,68,77,84,93,100,109,116,125,132,141,148,157,
%T A173512 164,173,180,189,196,205,212,221,228,237,244,253,260,269,276,285,292,
%U A173512 301,308,317,324,333,340,349,356,365,372,381,388,397,404,413,420,429,436
%N A173512 a(n) = 8*n + 4 + n mod 2.
%C A173512 First differences of A173511;
%C A173512 a(n+1) - a(n) = A010729(n+1).
%H A173512 <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (1, 1, -1).
%F A173512 G.f.: (4 + 9*x + 3*x^2)/((1 + x)*(1 - x)^2). - _Philippe Deléham_, Nov 29 2016
%t A173512 LinearRecurrence[{1, 1, -1}, {4, 13, 20}, 60] (* _Vincenzo Librandi_, Nov 29 2016 *)
%o A173512 (Magma) [8*n+4+n mod 2: n in [0..60]]; // _Vincenzo Librandi_, Nov 29 2016
%K A173512 nonn
%O A173512 0,1
%A A173512 _Reinhard Zumkeller_, Feb 20 2010