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 A144796 #18 Jul 25 2021 03:49:43
%S A144796 5,215,4517,248087,5212613,286292183,6015350885,330380931095,
%T A144796 6941709708677,381259308191447,8010726988462373,439972911271998743,
%U A144796 9244372002975869765,507728358348578357975,10667997280707165246437
%N A144796 Expansion of x(5+215x-1253x^2-23x^3)/((1+34x+x^2)(1-34x+x^2)).
%C A144796 The original definition "Numbers n such that (n^2-17)/2 is a square" describes A077242. - _R. J. Mathar_, Nov 27 2011
%H A144796 <a href="/index/Rec#order_04">Index entries for linear recurrences with constant coefficients</a>, signature (0,1154,0,-1).
%F A144796 a(n) = 1154*a(n-2) - a(n-4).
%t A144796 Rest[CoefficientList[Series[x (5+215x-1253x^2-23x^3)/((1+34x+x^2)(1-34x+x^2)),{x,0,30}],x]] (* or *) LinearRecurrence[{0,1154,0,-1},{5,215,4517,248087},30] (* _Harvey P. Dale_, Apr 04 2014 *)
%o A144796 (PARI) Vec(x(5+215*x-1253*x^2-23*x^3)/((1+34*x+x^2)*(1-34*x+x^2))+O(x^99)) \\ _Charles R Greathouse IV_, Sep 26 2012
%K A144796 nonn,easy
%O A144796 1,1
%A A144796 _Richard Choulet_, Sep 21 2008