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 A017582 #19 Jul 19 2019 12:02:15
%S A017582 25,289,841,1681,2809,4225,5929,7921,10201,12769,15625,18769,22201,
%T A017582 25921,29929,34225,38809,43681,48841,54289,60025,66049,72361,78961,
%U A017582 85849,93025,100489,108241,116281
%N A017582 a(n) = (12n + 5)^2.
%H A017582 <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (3,-3,1).
%F A017582 a(n) = A017581(n)^2. - _Michel Marcus_, Dec 28 2014
%F A017582 G.f.: (25 + 214*x + 49*x^2)/(1-x)^3. - _Vincenzo Librandi_, Dec 28 2014
%t A017582 lst={};Do[AppendTo[lst,(12*n+5)^2],{n,0,5!}];lst (* _Vladimir Joseph Stephan Orlovsky_, Jun 29 2009 *)
%t A017582 CoefficientList[Series[(25 + 214 x + 49 x^2) / (1 - x)^3, {x, 0, 40}], x] (* _Vincenzo Librandi_, Dec 28 2014 *)
%t A017582 (12*Range[0,30]+5)^2 (* or *) LinearRecurrence[{3,-3,1},{25,289,841},30] (* _Harvey P. Dale_, Jul 19 2019 *)
%o A017582 (PARI) a(n)=(12*n+5)^2 \\ _Charles R Greathouse IV_, Jun 17 2017
%K A017582 nonn,easy
%O A017582 0,1
%A A017582 _N. J. A. Sloane_