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 A164267 #22 Sep 08 2022 08:45:47
%S A164267 0,1,2,7,16,46,114,309,792,2101,5456,14356,37468,98281,256998,673323,
%T A164267 1761984,4614226,12078110,31624285,82787980,216750601,567446112,
%U A164267 1485616392,3889356696,10182528721,26658108074,69791991919,182717549872
%N A164267 A Fibonacci convolution.
%H A164267 G. C. Greubel, <a href="/A164267/b164267.txt">Table of n, a(n) for n = 0..1000</a>
%H A164267 <a href="/index/Rec#order_04">Index entries for linear recurrences with constant coefficients</a>, signature (2,3,-4,1)
%F A164267 G.f.: x/((1+x-x^2)(1-3x+x^2)).
%F A164267 a(n) = Sum_{k=0..n} (-1)^k*F(k+1)*F(2(n-k)).
%F A164267 a(n) = Sum_{k=0..n} C(n,k)*F(k+1)*(1-(-1)^(n-k))/2.
%F A164267 a(n) = 2*a(n-1) + 3*a(n-2) - 4*a(n-3) + a(n-4).
%F A164267 a(n) = (A122367(n) - A039834(n-1))/2. - _R. J. Mathar_, Aug 17 2009
%t A164267 LinearRecurrence[{2,3,-4,1},{0,1,2,7},30] (* _Harvey P. Dale_, Jul 12 2011 *)
%t A164267 CoefficientList[Series[x / ((1 + x - x^2) (1 - 3 x + x^2)), {x, 0, 33}], x] (* _Vincenzo Librandi_, Sep 13 2017 *)
%o A164267 (PARI) x='x+O('x^50); concat([0], Vec(x/((1+x-x^2)*(1-3*x+x^2)))) \\ _G. C. Greubel_, Sep 12 2017
%o A164267 (Magma) I:=[0,1,2,7]; [n le 4 select I[n] else 2*Self(n-1)+3*Self(n-2)-4*Self(n-3)+Self(n-4): n in [1..30]]; // _Vincenzo Librandi_, Sep 13 2017
%K A164267 easy,nonn
%O A164267 0,3
%A A164267 _Paul Barry_, Aug 11 2009