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 A012772 #23 Jul 08 2025 02:47:03
%S A012772 1,3,12,49,200,816,3329,13581,55405,226030,922111,3761840,15346786,
%T A012772 62608681,255418101,1042002567,4250949112,17342153393,70748973084,
%U A012772 288627200960,1177482265857,4803651498529,19596955630177
%N A012772 Take every 5th term of Padovan sequence A000931, beginning with the sixth term.
%H A012772 Vincenzo Librandi, <a href="/A012772/b012772.txt">Table of n, a(n) for n = 0..1000</a>
%H A012772 <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (5, -4, 1).
%F A012772 a(n+3) = 5*a(n+2) - 4*a(n+1) + a(n).
%F A012772 G.f.: (1-x)^2/(1-5*x+4*x^2-x^3). - _Colin Barker_, Feb 02 2012
%t A012772 CoefficientList[Series[(1-x)^2/(1-5*x+4*x^2-x^3),{x,0,33}],x] (* _Vincenzo Librandi_, Apr 18 2012 *)
%t A012772 LinearRecurrence[{5,-4,1},{1,3,12},30] (* _Harvey P. Dale_, Aug 15 2024 *)
%o A012772 (Magma) I:=[1, 3, 12]; [n le 3 select I[n] else 5*Self(n-1)-4*Self(n-2)+Self(n-3): n in [1..30]]; // _Vincenzo Librandi_, Apr 18 2012
%Y A012772 Cf. A012781 (partial sums).
%K A012772 nonn,easy
%O A012772 0,2
%A A012772 _N. J. A. Sloane_