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 A190964 #30 Jan 11 2024 00:48:10
%S A190964 0,1,3,-1,-33,-89,63,1079,2607,-2969,-34977,-75241,124047,1124551,
%T A190964 2133183,-4845961,-35869713,-59149529,181248543,1135240919,1593237327,
%U A190964 -6572697209,-35650464897,-41224422601,232831381167,1110738369511,1003901296863,-8095679804521
%N A190964 a(n) = 3*a(n-1) - 10*a(n-2), with a(0)=0, a(1)=1.
%H A190964 G. C. Greubel, <a href="/A190964/b190964.txt">Table of n, a(n) for n = 0..1000</a>
%H A190964 <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (3,-10).
%F A190964 G.f.: x/(1-3*x+10*x^2). - _Philippe Deléham_, Oct 11 2011
%F A190964 From _G. C. Greubel_, Jan 11 2024: (Start)
%F A190964 a(n) = 10^((n-1)/2)*ChebyshevU(n-1, 3/(2*sqrt(10))).
%F A190964 E.g.f.: (2/sqrt(31))*exp(3*x/2)*sin(sqrt(31)*x/2). (End)
%t A190964 LinearRecurrence[{3,-10}, {0,1}, 50]
%o A190964 (PARI) my(x='x+O('x^30)); concat([0], Vec(x/(1-3*x+10*x^2))) \\ _G. C. Greubel_, Jan 25 2018
%o A190964 (Magma) I:=[0,1]; [n le 2 select I[n] else 3*Self(n-1) - 10*Self(n-2): n in [1..30]]; // _G. C. Greubel_, Jan 25 2018
%o A190964 (SageMath)
%o A190964 A190964=BinaryRecurrenceSequence(3,-10,0,1)
%o A190964 [A190964(n) for n in range(41)] # _G. C. Greubel_, Jan 11 2024
%Y A190964 Cf. A190958 (index to generalized Fibonacci sequences).
%K A190964 sign
%O A190964 0,3
%A A190964 _Vladimir Joseph Stephan Orlovsky_, May 24 2011