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 A138614 #12 Dec 29 2023 10:37:31
%S A138614 1,-1,-1,0,-4,2,-6,4,-4,4,4,0,16,-8,24,-16,16,-16,-16,0,-64,32,-96,64,
%T A138614 -64,64,64,0,256,-128,384,-256,256,-256,-256,0,-1024,512,-1536,1024,
%U A138614 -1024,1024,1024,0,4096,-2048,6144,-4096,4096,-4096,-4096
%N A138614 Expansion of (2*x-1)*(x^2-x-1) / ( 1-2*x^2+2*x^4 ).
%H A138614 <a href="/index/Rec">Index entries for linear recurrences with constant coefficients</a>, signature (0,2,0,-2).
%F A138614 a(n)= -4a(n-8).
%F A138614 a(n) = A138231(n+1)-2*A138231(n).
%F A138614 a(n) = A138232(n)- A138231(n).
%t A138614 LinearRecurrence[{0,2,0,-2},{1,-1,-1,0},60] (* _Harvey P. Dale_, Jul 31 2023 *)
%K A138614 sign,easy
%O A138614 0,5
%A A138614 _Paul Curtz_, May 14 2008